Key clinical point: Atopic dermatitis (AD) is associated with a lower risk for venous thromboembolism (VTE) than several rheumatologic and gastrointestinal immune-mediated inflammatory diseases (IMID).

Major finding: Patients with AD vs AD-matched control individuals did not have a higher risk for VTE (adjusted hazard ratio [aHR] 0.96; 95% CI 0.90-1.02). Compared with patients having AD, those with Crohn’s disease (aHR 1.71; 95% CI 1.47-1.99), rheumatoid arthritis (aHR 1.57; 95% CI 1.43-1.72), ulcerative colitis (aHR 1.84; 95% CI 1.63-2.09), and ankylosing spondylitis (aHR 1.45; 95% CI 1.03-2.03) had higher risks for VTE.

Study details: This retrospective observational cohort study analyzed 2,061,222 adult patients with IMID, including 1,098,633 patients with AD who were matched with 1,098,633 control individuals without IMID.

Disclosures: This study was funded by AbbVie Inc. JF Merola declared being a consultant or investigator for AbbVie and others. The other authors declared being current or former employees of or owning stocks or stock options in AbbVie.

Source: Merola JF et al. Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data. J Am Acad Dermatol. 2023 (Dec 23). doi: 10.1016/j.jaad.2023.12.027

Key clinical point: Atopic dermatitis (AD) is associated with a lower risk for venous thromboembolism (VTE) than several rheumatologic and gastrointestinal immune-mediated inflammatory diseases (IMID).

Major finding: Patients with AD vs AD-matched control individuals did not have a higher risk for VTE (adjusted hazard ratio [aHR] 0.96; 95% CI 0.90-1.02). Compared with patients having AD, those with Crohn’s disease (aHR 1.71; 95% CI 1.47-1.99), rheumatoid arthritis (aHR 1.57; 95% CI 1.43-1.72), ulcerative colitis (aHR 1.84; 95% CI 1.63-2.09), and ankylosing spondylitis (aHR 1.45; 95% CI 1.03-2.03) had higher risks for VTE.

Study details: This retrospective observational cohort study analyzed 2,061,222 adult patients with IMID, including 1,098,633 patients with AD who were matched with 1,098,633 control individuals without IMID.

Disclosures: This study was funded by AbbVie Inc. JF Merola declared being a consultant or investigator for AbbVie and others. The other authors declared being current or former employees of or owning stocks or stock options in AbbVie.

Source: Merola JF et al. Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data. J Am Acad Dermatol. 2023 (Dec 23). doi: 10.1016/j.jaad.2023.12.027

Key clinical point: Atopic dermatitis (AD) is associated with a lower risk for venous thromboembolism (VTE) than several rheumatologic and gastrointestinal immune-mediated inflammatory diseases (IMID).

Major finding: Patients with AD vs AD-matched control individuals did not have a higher risk for VTE (adjusted hazard ratio [aHR] 0.96; 95% CI 0.90-1.02). Compared with patients having AD, those with Crohn’s disease (aHR 1.71; 95% CI 1.47-1.99), rheumatoid arthritis (aHR 1.57; 95% CI 1.43-1.72), ulcerative colitis (aHR 1.84; 95% CI 1.63-2.09), and ankylosing spondylitis (aHR 1.45; 95% CI 1.03-2.03) had higher risks for VTE.

Study details: This retrospective observational cohort study analyzed 2,061,222 adult patients with IMID, including 1,098,633 patients with AD who were matched with 1,098,633 control individuals without IMID.

Disclosures: This study was funded by AbbVie Inc. JF Merola declared being a consultant or investigator for AbbVie and others. The other authors declared being current or former employees of or owning stocks or stock options in AbbVie.

Source: Merola JF et al. Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data. J Am Acad Dermatol. 2023 (Dec 23). doi: 10.1016/j.jaad.2023.12.027

In a lifelong smoker, a tumor in the periphery of the lung and histology showing glandular cells with some neuroendocrine differentiation is most likely large cell carcinoma, a type of non–small cell lung cancer (NSCLC). Although small cell lung cancer is also associated with smoking, histology typically demonstrates highly cellular aspirates with small blue cells with very scant or null cytoplasm, loosely arranged or in a syncytial pattern. Bronchial adenoma is unlikely, given the patient's unintentional weight loss and fatigue over the past few months. Mesothelioma is most associated with asbestos exposure and is found in the lung pleura, which typically presents with pleural effusion.

Lung cancer is the top cause of cancer deaths in the US, second only to prostate cancer in men and breast cancer in women; approximately 85% of all lung cancers are classified as NSCLC. Histologically, NSCLC is further categorized into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma (LCC). When a patient presents with intrathoracic symptoms (including cough, chest pain, wheezing, or dyspnea) and a pulmonary nodule on chest radiography, NSCLC is typically suspected as a possible diagnosis. Smoking is the most common cause of this lung cancer (78% in men, 90% in women). 

Several methods confirm the diagnosis of NSCLC, including bronchoscopy, sputum cytology, mediastinoscopy, thoracentesis, thoracoscopy, and transthoracic needle biopsy. Which method is chosen depends on the primary lesion location and accessibility. Histologic evaluation helps differentiate between the various subtypes of NSCLC. LCC is a subset of NSCLC that is a diagnosis of exclusion. Histologically, LCC is poorly differentiated, and 90% of cases will show squamous, glandular, or neuroendocrine differentiation.

When first diagnosed with NSCLC, 20% of patients have cancer confined to a specific area, 25% of patients have cancer that has spread to nearby areas, and 55% of patients have cancer that has spread to distant body parts. The specific symptoms experienced by patients will vary depending on the location of the cancer. The prognosis for NSCLC depends on the staging of the tumor, nodes, and metastases, the patient's performance status, and any existing health conditions. In the US, the 5-year relative survival rate is 61.2% for localized disease, 33.5% for regional disease, and 7.0% for disease with distant metastases. 

Treatment of NSCLC also varies according to the patient's functional status, tumor stage, molecular characteristics, and comorbidities. Generally, patients with stage I, II, or III NSCLC are treated with the intent to cure, which can include surgery, chemotherapy, radiation therapy, or a combined approach. Lobectomy or resection is generally accepted as an approach for surgical intervention on early-stage NSCLC; however, for stages higher than IB (including stage II/III), patients are recommended to undergo adjuvant chemotherapy. Patients with stage IV disease (or recurrence after initial management) are typically treated with systemic therapy or should be considered for palliative treatment to improve quality of life and overall survival.
 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

In a lifelong smoker, a tumor in the periphery of the lung and histology showing glandular cells with some neuroendocrine differentiation is most likely large cell carcinoma, a type of non–small cell lung cancer (NSCLC). Although small cell lung cancer is also associated with smoking, histology typically demonstrates highly cellular aspirates with small blue cells with very scant or null cytoplasm, loosely arranged or in a syncytial pattern. Bronchial adenoma is unlikely, given the patient's unintentional weight loss and fatigue over the past few months. Mesothelioma is most associated with asbestos exposure and is found in the lung pleura, which typically presents with pleural effusion.

Lung cancer is the top cause of cancer deaths in the US, second only to prostate cancer in men and breast cancer in women; approximately 85% of all lung cancers are classified as NSCLC. Histologically, NSCLC is further categorized into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma (LCC). When a patient presents with intrathoracic symptoms (including cough, chest pain, wheezing, or dyspnea) and a pulmonary nodule on chest radiography, NSCLC is typically suspected as a possible diagnosis. Smoking is the most common cause of this lung cancer (78% in men, 90% in women). 

Several methods confirm the diagnosis of NSCLC, including bronchoscopy, sputum cytology, mediastinoscopy, thoracentesis, thoracoscopy, and transthoracic needle biopsy. Which method is chosen depends on the primary lesion location and accessibility. Histologic evaluation helps differentiate between the various subtypes of NSCLC. LCC is a subset of NSCLC that is a diagnosis of exclusion. Histologically, LCC is poorly differentiated, and 90% of cases will show squamous, glandular, or neuroendocrine differentiation.

When first diagnosed with NSCLC, 20% of patients have cancer confined to a specific area, 25% of patients have cancer that has spread to nearby areas, and 55% of patients have cancer that has spread to distant body parts. The specific symptoms experienced by patients will vary depending on the location of the cancer. The prognosis for NSCLC depends on the staging of the tumor, nodes, and metastases, the patient's performance status, and any existing health conditions. In the US, the 5-year relative survival rate is 61.2% for localized disease, 33.5% for regional disease, and 7.0% for disease with distant metastases. 

Treatment of NSCLC also varies according to the patient's functional status, tumor stage, molecular characteristics, and comorbidities. Generally, patients with stage I, II, or III NSCLC are treated with the intent to cure, which can include surgery, chemotherapy, radiation therapy, or a combined approach. Lobectomy or resection is generally accepted as an approach for surgical intervention on early-stage NSCLC; however, for stages higher than IB (including stage II/III), patients are recommended to undergo adjuvant chemotherapy. Patients with stage IV disease (or recurrence after initial management) are typically treated with systemic therapy or should be considered for palliative treatment to improve quality of life and overall survival.
 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

In a lifelong smoker, a tumor in the periphery of the lung and histology showing glandular cells with some neuroendocrine differentiation is most likely large cell carcinoma, a type of non–small cell lung cancer (NSCLC). Although small cell lung cancer is also associated with smoking, histology typically demonstrates highly cellular aspirates with small blue cells with very scant or null cytoplasm, loosely arranged or in a syncytial pattern. Bronchial adenoma is unlikely, given the patient's unintentional weight loss and fatigue over the past few months. Mesothelioma is most associated with asbestos exposure and is found in the lung pleura, which typically presents with pleural effusion.

Lung cancer is the top cause of cancer deaths in the US, second only to prostate cancer in men and breast cancer in women; approximately 85% of all lung cancers are classified as NSCLC. Histologically, NSCLC is further categorized into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma (LCC). When a patient presents with intrathoracic symptoms (including cough, chest pain, wheezing, or dyspnea) and a pulmonary nodule on chest radiography, NSCLC is typically suspected as a possible diagnosis. Smoking is the most common cause of this lung cancer (78% in men, 90% in women). 

Several methods confirm the diagnosis of NSCLC, including bronchoscopy, sputum cytology, mediastinoscopy, thoracentesis, thoracoscopy, and transthoracic needle biopsy. Which method is chosen depends on the primary lesion location and accessibility. Histologic evaluation helps differentiate between the various subtypes of NSCLC. LCC is a subset of NSCLC that is a diagnosis of exclusion. Histologically, LCC is poorly differentiated, and 90% of cases will show squamous, glandular, or neuroendocrine differentiation.

When first diagnosed with NSCLC, 20% of patients have cancer confined to a specific area, 25% of patients have cancer that has spread to nearby areas, and 55% of patients have cancer that has spread to distant body parts. The specific symptoms experienced by patients will vary depending on the location of the cancer. The prognosis for NSCLC depends on the staging of the tumor, nodes, and metastases, the patient's performance status, and any existing health conditions. In the US, the 5-year relative survival rate is 61.2% for localized disease, 33.5% for regional disease, and 7.0% for disease with distant metastases. 

Treatment of NSCLC also varies according to the patient's functional status, tumor stage, molecular characteristics, and comorbidities. Generally, patients with stage I, II, or III NSCLC are treated with the intent to cure, which can include surgery, chemotherapy, radiation therapy, or a combined approach. Lobectomy or resection is generally accepted as an approach for surgical intervention on early-stage NSCLC; however, for stages higher than IB (including stage II/III), patients are recommended to undergo adjuvant chemotherapy. Patients with stage IV disease (or recurrence after initial management) are typically treated with systemic therapy or should be considered for palliative treatment to improve quality of life and overall survival.
 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Given the patient's results on the genetic panel and MRI, as well as the noted cognitive decline and increased aggression, this patient is suspected of having limbic-predominant age-related TDP-43 encephalopathy (LATE) secondary to AD and is referred to the neurologist on her multidisciplinary care team for further consultation and testing.

AD is one of the most common forms of dementia. More than 6 million people in the United States have clinical AD or mild cognitive impairment because of AD. LATE is a new classification of dementia, identified in 2019, that mimics AD but is a unique disease entity driven by the misfolding of the protein TDP-43, which regulates gene expression in the brain. Misfolded TDP-43 protein is common among older adults aged ≥ 85 years, and about a quarter of this population has enough misfolded TDP-43 protein to affect their memory and cognition. 

Diagnosing AD currently relies on a clinical approach. A complete physical examination, with a detailed neurologic examination and a mental status examination, is used to evaluate disease stage. Initial mental status testing evaluates attention and concentration, recent and remote memory, language, praxis, executive function, and visuospatial function. Because LATE is a newly discovered form of dementia, there are no set guidelines on diagnosing LATE and no robust biomarker for TDP-43. What is known about LATE has been gleaned mostly from retrospective clinicopathologic studies. 

The LATE consensus working group reports that the clinical course of disease, as studied by autopsy-proven LATE neuropathologic change (LATE-NC), is described as an "amnestic cognitive syndrome that can evolve to incorporate multiple cognitive domains and ultimately to impair activities of daily living." Researchers are currently analyzing different clinical assessments and neuroimaging with MRI to characterize LATE. A group of international researchers recently published a set of clinical criteria for limbic-predominant amnestic neurodegenerative syndrome (LANS), which is associated with LATE-NC. Their criteria include "core, standard and advanced features that are measurable in vivo, including older age at evaluation, mild clinical syndrome, disproportionate hippocampal atrophy, impaired semantic memory, limbic hypometabolism, absence of neocortical degenerative patterns and low likelihood of neocortical tau, with degrees of certainty (highest, high, moderate, low)." Other neuroimaging studies of autopsy-confirmed LATE-NC have shown that atrophy is mostly focused in the medial temporal lobe with marked reduced hippocampal volume.

The group reports that LATE and AD probably share pathophysiologic mechanisms. One of the universally accepted hallmarks of AD is the formation of beta-amyloid plaques, which are dense, mostly insoluble deposits of beta-amyloid protein that develop around neurons in the hippocampus and other regions in the cerebral cortex used for decision-making. These plaques disrupt brain function and lead to brain atrophy. The LATE group also reports that this same pathology has been noted with LATE: "Many subjects with LATE-NC have comorbid brain pathologies, often including amyloid-beta plaques and tauopathy." That said, genetic studies have helped identify five genes with risk alleles for LATE (GRN, TMEM106B, ABCC9, KCNMB2, and APOE), suggesting disease-specific underlying mechanisms compared to AD. 

Patient and caregiver education and guidance is vital with a dementia diagnosis. If LATE and/or AD are suspected, physicians should encourage the involvement of family and friends who agree to become more involved in the patient's care as the disease progresses. These individuals need to understand the patient's wishes around care, especially for the future when the patient is no longer able to make decisions. The patient may also consider establishing medical advance directives and durable power of attorney for medical and financial decision-making. Caregivers supporting the patient are encouraged to help balance the physical needs of the patient while maintaining respect for them as a competent adult to the extent allowed by the progression of their disease. 

Because LATE is a new classification of dementia, there are no known effective treatments. One ongoing study is testing the use of autologous bone marrow–derived stem cells to help improve cognitive impairment among patients with LATE, AD, and other dementias. Current AD treatments are focused on symptomatic therapies that modulate neurotransmitters — either acetylcholine or glutamate. The standard medical treatment includes cholinesterase inhibitors and a partial N-methyl-D-aspartate antagonist. Two amyloid-directed antibodies (aducanumab, lecanemab) are currently available in the United States for individuals with AD exhibiting mild cognitive impairment or mild dementia. A third agent currently in clinical trials (donanemab) has shown significantly slowed clinical progression after 1.5 years among clinical trial participants with early symptomatic AD and amyloid and tau pathology.

Shaheen E. Lakhan, MD, PhD, MS, MEd, Chief of Pain Management, Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke, Virginia.

Disclosure: Shaheen E. Lakhan, MD, PhD, MS, MEd, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Given the patient's results on the genetic panel and MRI, as well as the noted cognitive decline and increased aggression, this patient is suspected of having limbic-predominant age-related TDP-43 encephalopathy (LATE) secondary to AD and is referred to the neurologist on her multidisciplinary care team for further consultation and testing.

AD is one of the most common forms of dementia. More than 6 million people in the United States have clinical AD or mild cognitive impairment because of AD. LATE is a new classification of dementia, identified in 2019, that mimics AD but is a unique disease entity driven by the misfolding of the protein TDP-43, which regulates gene expression in the brain. Misfolded TDP-43 protein is common among older adults aged ≥ 85 years, and about a quarter of this population has enough misfolded TDP-43 protein to affect their memory and cognition. 

Diagnosing AD currently relies on a clinical approach. A complete physical examination, with a detailed neurologic examination and a mental status examination, is used to evaluate disease stage. Initial mental status testing evaluates attention and concentration, recent and remote memory, language, praxis, executive function, and visuospatial function. Because LATE is a newly discovered form of dementia, there are no set guidelines on diagnosing LATE and no robust biomarker for TDP-43. What is known about LATE has been gleaned mostly from retrospective clinicopathologic studies. 

The LATE consensus working group reports that the clinical course of disease, as studied by autopsy-proven LATE neuropathologic change (LATE-NC), is described as an "amnestic cognitive syndrome that can evolve to incorporate multiple cognitive domains and ultimately to impair activities of daily living." Researchers are currently analyzing different clinical assessments and neuroimaging with MRI to characterize LATE. A group of international researchers recently published a set of clinical criteria for limbic-predominant amnestic neurodegenerative syndrome (LANS), which is associated with LATE-NC. Their criteria include "core, standard and advanced features that are measurable in vivo, including older age at evaluation, mild clinical syndrome, disproportionate hippocampal atrophy, impaired semantic memory, limbic hypometabolism, absence of neocortical degenerative patterns and low likelihood of neocortical tau, with degrees of certainty (highest, high, moderate, low)." Other neuroimaging studies of autopsy-confirmed LATE-NC have shown that atrophy is mostly focused in the medial temporal lobe with marked reduced hippocampal volume.

The group reports that LATE and AD probably share pathophysiologic mechanisms. One of the universally accepted hallmarks of AD is the formation of beta-amyloid plaques, which are dense, mostly insoluble deposits of beta-amyloid protein that develop around neurons in the hippocampus and other regions in the cerebral cortex used for decision-making. These plaques disrupt brain function and lead to brain atrophy. The LATE group also reports that this same pathology has been noted with LATE: "Many subjects with LATE-NC have comorbid brain pathologies, often including amyloid-beta plaques and tauopathy." That said, genetic studies have helped identify five genes with risk alleles for LATE (GRN, TMEM106B, ABCC9, KCNMB2, and APOE), suggesting disease-specific underlying mechanisms compared to AD. 

Patient and caregiver education and guidance is vital with a dementia diagnosis. If LATE and/or AD are suspected, physicians should encourage the involvement of family and friends who agree to become more involved in the patient's care as the disease progresses. These individuals need to understand the patient's wishes around care, especially for the future when the patient is no longer able to make decisions. The patient may also consider establishing medical advance directives and durable power of attorney for medical and financial decision-making. Caregivers supporting the patient are encouraged to help balance the physical needs of the patient while maintaining respect for them as a competent adult to the extent allowed by the progression of their disease. 

Because LATE is a new classification of dementia, there are no known effective treatments. One ongoing study is testing the use of autologous bone marrow–derived stem cells to help improve cognitive impairment among patients with LATE, AD, and other dementias. Current AD treatments are focused on symptomatic therapies that modulate neurotransmitters — either acetylcholine or glutamate. The standard medical treatment includes cholinesterase inhibitors and a partial N-methyl-D-aspartate antagonist. Two amyloid-directed antibodies (aducanumab, lecanemab) are currently available in the United States for individuals with AD exhibiting mild cognitive impairment or mild dementia. A third agent currently in clinical trials (donanemab) has shown significantly slowed clinical progression after 1.5 years among clinical trial participants with early symptomatic AD and amyloid and tau pathology.

Shaheen E. Lakhan, MD, PhD, MS, MEd, Chief of Pain Management, Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke, Virginia.

Disclosure: Shaheen E. Lakhan, MD, PhD, MS, MEd, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Given the patient's results on the genetic panel and MRI, as well as the noted cognitive decline and increased aggression, this patient is suspected of having limbic-predominant age-related TDP-43 encephalopathy (LATE) secondary to AD and is referred to the neurologist on her multidisciplinary care team for further consultation and testing.

AD is one of the most common forms of dementia. More than 6 million people in the United States have clinical AD or mild cognitive impairment because of AD. LATE is a new classification of dementia, identified in 2019, that mimics AD but is a unique disease entity driven by the misfolding of the protein TDP-43, which regulates gene expression in the brain. Misfolded TDP-43 protein is common among older adults aged ≥ 85 years, and about a quarter of this population has enough misfolded TDP-43 protein to affect their memory and cognition. 

Diagnosing AD currently relies on a clinical approach. A complete physical examination, with a detailed neurologic examination and a mental status examination, is used to evaluate disease stage. Initial mental status testing evaluates attention and concentration, recent and remote memory, language, praxis, executive function, and visuospatial function. Because LATE is a newly discovered form of dementia, there are no set guidelines on diagnosing LATE and no robust biomarker for TDP-43. What is known about LATE has been gleaned mostly from retrospective clinicopathologic studies. 

The LATE consensus working group reports that the clinical course of disease, as studied by autopsy-proven LATE neuropathologic change (LATE-NC), is described as an "amnestic cognitive syndrome that can evolve to incorporate multiple cognitive domains and ultimately to impair activities of daily living." Researchers are currently analyzing different clinical assessments and neuroimaging with MRI to characterize LATE. A group of international researchers recently published a set of clinical criteria for limbic-predominant amnestic neurodegenerative syndrome (LANS), which is associated with LATE-NC. Their criteria include "core, standard and advanced features that are measurable in vivo, including older age at evaluation, mild clinical syndrome, disproportionate hippocampal atrophy, impaired semantic memory, limbic hypometabolism, absence of neocortical degenerative patterns and low likelihood of neocortical tau, with degrees of certainty (highest, high, moderate, low)." Other neuroimaging studies of autopsy-confirmed LATE-NC have shown that atrophy is mostly focused in the medial temporal lobe with marked reduced hippocampal volume.

The group reports that LATE and AD probably share pathophysiologic mechanisms. One of the universally accepted hallmarks of AD is the formation of beta-amyloid plaques, which are dense, mostly insoluble deposits of beta-amyloid protein that develop around neurons in the hippocampus and other regions in the cerebral cortex used for decision-making. These plaques disrupt brain function and lead to brain atrophy. The LATE group also reports that this same pathology has been noted with LATE: "Many subjects with LATE-NC have comorbid brain pathologies, often including amyloid-beta plaques and tauopathy." That said, genetic studies have helped identify five genes with risk alleles for LATE (GRN, TMEM106B, ABCC9, KCNMB2, and APOE), suggesting disease-specific underlying mechanisms compared to AD. 

Patient and caregiver education and guidance is vital with a dementia diagnosis. If LATE and/or AD are suspected, physicians should encourage the involvement of family and friends who agree to become more involved in the patient's care as the disease progresses. These individuals need to understand the patient's wishes around care, especially for the future when the patient is no longer able to make decisions. The patient may also consider establishing medical advance directives and durable power of attorney for medical and financial decision-making. Caregivers supporting the patient are encouraged to help balance the physical needs of the patient while maintaining respect for them as a competent adult to the extent allowed by the progression of their disease. 

Because LATE is a new classification of dementia, there are no known effective treatments. One ongoing study is testing the use of autologous bone marrow–derived stem cells to help improve cognitive impairment among patients with LATE, AD, and other dementias. Current AD treatments are focused on symptomatic therapies that modulate neurotransmitters — either acetylcholine or glutamate. The standard medical treatment includes cholinesterase inhibitors and a partial N-methyl-D-aspartate antagonist. Two amyloid-directed antibodies (aducanumab, lecanemab) are currently available in the United States for individuals with AD exhibiting mild cognitive impairment or mild dementia. A third agent currently in clinical trials (donanemab) has shown significantly slowed clinical progression after 1.5 years among clinical trial participants with early symptomatic AD and amyloid and tau pathology.

Shaheen E. Lakhan, MD, PhD, MS, MEd, Chief of Pain Management, Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke, Virginia.

Disclosure: Shaheen E. Lakhan, MD, PhD, MS, MEd, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Migraine is one of the most common neurologic diseases, affecting about 14% of the population. Migraines may also be associated with auras or visual or sensory symptoms that precede the headache. However, approximately 4% of people with migraine experience their usual migraines and sometimes also experience episodes of an aura that is not followed by a headache. Silent migraines, also known as acephalgic migraines or "migraine auras without headache," typically cause symptoms that accompany the phases of a migraine, but without the classic headache pain. It is most common among young adults in their 20s and 30s and older adults between 40 and 60 years of age, especially in those who had auras accompanied by migraine headaches when younger. 

According to the International Headache Society, a migraine aura develops gradually over 5 to 10 minutes and lasts for less than 1 hour. Although the symptoms of a silent migraine may vary from person to person, visual symptoms occur in more than 90% of migraine auras. Visual symptoms may also be accompanied by other neurologic symptoms such as dizziness, numbness or tingling, and aphasia. The most common visual symptoms are positive symptoms, such as flash scotoma, visual distortion, colored spots, and flash hallucinations. Visual symptoms may easily be confused with symptoms of a transient ischemic attack (TIA). However, migraine auras generally last 15 to 30 minutes. They are often described as dynamic, bright, multicolored forms in geometric patterns. In contrast, the visual symptoms of a TIA last on average 3 to 10 minutes and are described as a static, dark dimming of vision. 

The diagnosis of migraine aura without headache should be made after all other possible causes have been excluded, particularly TIAs and focal seizures because of the diagnostic, therapeutic, and prognostic implications. Testing may include a neurologic and eye examination, MRI, CT angiography, and laboratory testing for clotting disorders. 

Migraine aura without headache is a benign condition and generally does not require treatment. When symptoms of silent migraines are severe enough, low-dose aspirin and calcium-channel blockers may be considered as treatment options. However, triptans, which are often used in patients with migraine headaches, should not be used to treat silent migraines because they do not act fast enough to affect an aura. In addition, triptans should be used with caution in older patients, who may have vascular disease, hypertension, and other cardiovascular risk factors. 
 

Jasmin Harpe, MD, MPH, Headache Fellow, Department of Neurology, Harvard University, John R. Graham Headache Center, Mass General Brigham, Boston, MA

Jasmin Harpe, MD, MPH, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Migraine is one of the most common neurologic diseases, affecting about 14% of the population. Migraines may also be associated with auras or visual or sensory symptoms that precede the headache. However, approximately 4% of people with migraine experience their usual migraines and sometimes also experience episodes of an aura that is not followed by a headache. Silent migraines, also known as acephalgic migraines or "migraine auras without headache," typically cause symptoms that accompany the phases of a migraine, but without the classic headache pain. It is most common among young adults in their 20s and 30s and older adults between 40 and 60 years of age, especially in those who had auras accompanied by migraine headaches when younger. 

According to the International Headache Society, a migraine aura develops gradually over 5 to 10 minutes and lasts for less than 1 hour. Although the symptoms of a silent migraine may vary from person to person, visual symptoms occur in more than 90% of migraine auras. Visual symptoms may also be accompanied by other neurologic symptoms such as dizziness, numbness or tingling, and aphasia. The most common visual symptoms are positive symptoms, such as flash scotoma, visual distortion, colored spots, and flash hallucinations. Visual symptoms may easily be confused with symptoms of a transient ischemic attack (TIA). However, migraine auras generally last 15 to 30 minutes. They are often described as dynamic, bright, multicolored forms in geometric patterns. In contrast, the visual symptoms of a TIA last on average 3 to 10 minutes and are described as a static, dark dimming of vision. 

The diagnosis of migraine aura without headache should be made after all other possible causes have been excluded, particularly TIAs and focal seizures because of the diagnostic, therapeutic, and prognostic implications. Testing may include a neurologic and eye examination, MRI, CT angiography, and laboratory testing for clotting disorders. 

Migraine aura without headache is a benign condition and generally does not require treatment. When symptoms of silent migraines are severe enough, low-dose aspirin and calcium-channel blockers may be considered as treatment options. However, triptans, which are often used in patients with migraine headaches, should not be used to treat silent migraines because they do not act fast enough to affect an aura. In addition, triptans should be used with caution in older patients, who may have vascular disease, hypertension, and other cardiovascular risk factors. 
 

Jasmin Harpe, MD, MPH, Headache Fellow, Department of Neurology, Harvard University, John R. Graham Headache Center, Mass General Brigham, Boston, MA

Jasmin Harpe, MD, MPH, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Migraine is one of the most common neurologic diseases, affecting about 14% of the population. Migraines may also be associated with auras or visual or sensory symptoms that precede the headache. However, approximately 4% of people with migraine experience their usual migraines and sometimes also experience episodes of an aura that is not followed by a headache. Silent migraines, also known as acephalgic migraines or "migraine auras without headache," typically cause symptoms that accompany the phases of a migraine, but without the classic headache pain. It is most common among young adults in their 20s and 30s and older adults between 40 and 60 years of age, especially in those who had auras accompanied by migraine headaches when younger. 

According to the International Headache Society, a migraine aura develops gradually over 5 to 10 minutes and lasts for less than 1 hour. Although the symptoms of a silent migraine may vary from person to person, visual symptoms occur in more than 90% of migraine auras. Visual symptoms may also be accompanied by other neurologic symptoms such as dizziness, numbness or tingling, and aphasia. The most common visual symptoms are positive symptoms, such as flash scotoma, visual distortion, colored spots, and flash hallucinations. Visual symptoms may easily be confused with symptoms of a transient ischemic attack (TIA). However, migraine auras generally last 15 to 30 minutes. They are often described as dynamic, bright, multicolored forms in geometric patterns. In contrast, the visual symptoms of a TIA last on average 3 to 10 minutes and are described as a static, dark dimming of vision. 

The diagnosis of migraine aura without headache should be made after all other possible causes have been excluded, particularly TIAs and focal seizures because of the diagnostic, therapeutic, and prognostic implications. Testing may include a neurologic and eye examination, MRI, CT angiography, and laboratory testing for clotting disorders. 

Migraine aura without headache is a benign condition and generally does not require treatment. When symptoms of silent migraines are severe enough, low-dose aspirin and calcium-channel blockers may be considered as treatment options. However, triptans, which are often used in patients with migraine headaches, should not be used to treat silent migraines because they do not act fast enough to affect an aura. In addition, triptans should be used with caution in older patients, who may have vascular disease, hypertension, and other cardiovascular risk factors. 
 

Jasmin Harpe, MD, MPH, Headache Fellow, Department of Neurology, Harvard University, John R. Graham Headache Center, Mass General Brigham, Boston, MA

Jasmin Harpe, MD, MPH, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Commonly known as neem or nimba, Azadirachta indica traditionally has been used as an oil or poultice to lighten skin pigment and reduce joint inflammation. Neem is a drought-resistant evergreen tree with thin serrated leaves, white fragrant flowers, and olivelike fruit (Figure 1). This plant is indigenous to India but also is readily found within tropical and semitropical environments throughout the Middle East, Southeast Asia, North Africa, and Australia.

Traditional Uses

For more than 4000 years, neem leaves, bark, fruit, and seeds have been used in food, insecticide, and herbal medicine cross-culturally in Indian Ayurvedic medicine and across Southeast Asia, particularly in Cambodia, Laos, Thailand, Myanmar, and Vietnam.^1-3 Because of its many essential nutrients—oleic acid, palmitic acid, stearic acid, linoleic acid, behenic acid, arachidic acid, and palmitoleic acid—and readily available nature, some ethnic groups include neem in their diet.⁴ Neem commonly is used as a seasoning in soups and rice, eaten as a cooked vegetable, infused into teas and tonics, and pickled with other spices.⁵

All parts of the neem tree—both externally and internally—have been utilized in traditional medicine for the treatment of various diseases and ailments. The flowers have been used to treat eye diseases and dyspepsia, the fruit has been employed as an anthelmintic, the seeds and leaves have been used for malaria treatment and insecticide, the stem bark has been used for the treatment of diarrhea, and the root bark has been used for skin diseases and inflammation.⁶ Neem oil is a yellow-brown bitter substance that often is utilized to treat skin diseases such as psoriasis, eczema, fungal infections, and abscesses.

Case Report—A 77-year-old man presented with a diffuse rash across the lower back. He reported that he had been using topical neem oil to alleviate lower back pain and arthritis for the last 6 months with noted relief and improvement of back pain. After roughly 3 to 4 months of using neem oil, he noted a rash on the lower back, bilateral flanks, and buttocks (Figure 2). The rash was asymptomatic, and he denied any pruritus, scaling, pain, or burning. The patient was referred to dermatology and received a diagnosis of chemical leukoderma secondary to contact with A indica. The patient was advised to stop using the topical neem oil, and the rash was simply monitored, as it was asymptomatic.

Bioactivity

Research has elucidated multiple bioactivity mechanisms of neem, including melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity.^1,7-9 Literature on the diverse phytochemical components of A indica indicate high levels of limonoids, flavonoids, and triterpenoids that are responsible for much of its antioxidant, anti-inflammatory, and insecticide properties.^1,10

Melanogenesis-Inhibitory Activity—To date, neem has been added to a number of cosmetic products used in Ayurvedic medicine. One study of isolated compounds in A indica showed superior inhibitory activities against melanogenesis with minimal toxicity to cells (86.5%–105.1% cell viability). Western blot analysis of samples extracted and isolated from neem root and bark showed melanogenesis-inhibitory activities in B16 melanoma cells through the inhibition of microphthalmia-associated transcription factor expression and decreased expression of tyrosinase, as well as tyrosinase-related proteins 1 and 2, which are largely responsible for melanin synthesis.¹¹ In another study, A indica flowers and their extracted constituents—6-deacetylnimbin and kaempferide—suggest melanogenesis-inhibitory activities in B16 melanoma cells with little to no toxicity to the cells (81.0%–111.7% cell viability).¹ In an evaluationof A indica seed extracts, some of the isolated limonoids and diterpenoids exhibited a marked melanogenesis-inhibitory effect (74%–91% reduction of melanin content) with no toxicity to the cell.⁵ All of these studies indicate that active compounds in neem root, bark, flowers, and seeds may be potential skin-lightening agents.

Toxicity Against Pests—Neem seeds have phytochemicals that convey some insecticidal properties. The seeds often are ground into a powder, combined with water, and sprayed onto crops to act as an insecticide. As a natural method of nonpesticidal management, A indica acts as an antifeedant, insect repellent, and egg-laying deterrent that protects crops from damage. Studies of A indica have noted effective nonpesticidal management against arthropod pests such as armyworm, termites, and the oriental fruit fly.^7,12,13

Antimalarial Activity—One study indicated that nimbolide, a limonoid from the neem plant, demonstrated antimalarial activity against Plasmodium falciparum. In separate cultures of asexual parasites and mature gametocytes, parasite numbers were less than 50% of the number in control cultures (8.0% vs 8.5% parasitemia, respectively).¹⁴ Thus, the lower parasite numbers indicated by this study highlight the antimalarial utility of nimbolide and neem oil.

Antioxidant and Anti-inflammatory Activity—Neem bark has been reported to have considerable antioxidant activity due to its high phenolic content.^1,15 One study showed that azadirachtin and nimbolide in neem exhibited concentration-dependent antiradical scavenging activity and antioxidant properties.¹⁶

The anti-inflammatory potential for neem may occur via the inhibition of the nuclear factor-κB signaling pathway, which is linked to cancer, inflammation, and apoptosis.¹⁷ It also has been observed that nimbidin within neem extracts—such as leaves, bark, and seed extract—suppresses the function of macrophages and neutrophils relevant to inflammation.¹⁶ Another study indicated neem’s anti-inflammatory activity due to the regulation of proinflammatory enzymes such as cyclooxygenase and lipoxygenase.¹⁸

Safety, Toxicity, and Risks

Ingestion—Although neem is safe to use in the general population, neem oil poisoning has been reported, particularly in young children. Ingesting large quantities of neem has resulted in vomiting, hepatic toxicity, metabolic acidosis, late neurologic sequelae, and encephalopathy in young children.¹⁹ The diagnosis of neem oil poisoning is based on patient history, clinical examination, and imaging findings. Poisoning can manifest as drowsiness, tachypnea, and generalized seizures.²⁰

Topical Application—Topical use of neem appears to be safe if the substance is diluted with other ingredients. However, direct application to the skin is not advised, as it may cause leukoderma and could induce allergic contact dermatitis and other allergic reactions.⁴

Final Thoughts

The use of neem extract for disease prevention and treatment has been prevalent around the world since ancient times. Neem has been documented to possess melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity by means of tyrosinase inhibition, phytochemical production, limonoid expression, and nuclear factor-κB regulation, respectively. However, topical use of neem may trigger a cutaneous response, highlighting the importance of considering a diagnosis of neem oil–induced chemical leukoderma when patients present with a hypopigmented rash and relevant history.

Commonly known as neem or nimba, Azadirachta indica traditionally has been used as an oil or poultice to lighten skin pigment and reduce joint inflammation. Neem is a drought-resistant evergreen tree with thin serrated leaves, white fragrant flowers, and olivelike fruit (Figure 1). This plant is indigenous to India but also is readily found within tropical and semitropical environments throughout the Middle East, Southeast Asia, North Africa, and Australia.

Traditional Uses

For more than 4000 years, neem leaves, bark, fruit, and seeds have been used in food, insecticide, and herbal medicine cross-culturally in Indian Ayurvedic medicine and across Southeast Asia, particularly in Cambodia, Laos, Thailand, Myanmar, and Vietnam.^1-3 Because of its many essential nutrients—oleic acid, palmitic acid, stearic acid, linoleic acid, behenic acid, arachidic acid, and palmitoleic acid—and readily available nature, some ethnic groups include neem in their diet.⁴ Neem commonly is used as a seasoning in soups and rice, eaten as a cooked vegetable, infused into teas and tonics, and pickled with other spices.⁵

All parts of the neem tree—both externally and internally—have been utilized in traditional medicine for the treatment of various diseases and ailments. The flowers have been used to treat eye diseases and dyspepsia, the fruit has been employed as an anthelmintic, the seeds and leaves have been used for malaria treatment and insecticide, the stem bark has been used for the treatment of diarrhea, and the root bark has been used for skin diseases and inflammation.⁶ Neem oil is a yellow-brown bitter substance that often is utilized to treat skin diseases such as psoriasis, eczema, fungal infections, and abscesses.

Case Report—A 77-year-old man presented with a diffuse rash across the lower back. He reported that he had been using topical neem oil to alleviate lower back pain and arthritis for the last 6 months with noted relief and improvement of back pain. After roughly 3 to 4 months of using neem oil, he noted a rash on the lower back, bilateral flanks, and buttocks (Figure 2). The rash was asymptomatic, and he denied any pruritus, scaling, pain, or burning. The patient was referred to dermatology and received a diagnosis of chemical leukoderma secondary to contact with A indica. The patient was advised to stop using the topical neem oil, and the rash was simply monitored, as it was asymptomatic.

Bioactivity

Research has elucidated multiple bioactivity mechanisms of neem, including melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity.^1,7-9 Literature on the diverse phytochemical components of A indica indicate high levels of limonoids, flavonoids, and triterpenoids that are responsible for much of its antioxidant, anti-inflammatory, and insecticide properties.^1,10

Melanogenesis-Inhibitory Activity—To date, neem has been added to a number of cosmetic products used in Ayurvedic medicine. One study of isolated compounds in A indica showed superior inhibitory activities against melanogenesis with minimal toxicity to cells (86.5%–105.1% cell viability). Western blot analysis of samples extracted and isolated from neem root and bark showed melanogenesis-inhibitory activities in B16 melanoma cells through the inhibition of microphthalmia-associated transcription factor expression and decreased expression of tyrosinase, as well as tyrosinase-related proteins 1 and 2, which are largely responsible for melanin synthesis.¹¹ In another study, A indica flowers and their extracted constituents—6-deacetylnimbin and kaempferide—suggest melanogenesis-inhibitory activities in B16 melanoma cells with little to no toxicity to the cells (81.0%–111.7% cell viability).¹ In an evaluationof A indica seed extracts, some of the isolated limonoids and diterpenoids exhibited a marked melanogenesis-inhibitory effect (74%–91% reduction of melanin content) with no toxicity to the cell.⁵ All of these studies indicate that active compounds in neem root, bark, flowers, and seeds may be potential skin-lightening agents.

Toxicity Against Pests—Neem seeds have phytochemicals that convey some insecticidal properties. The seeds often are ground into a powder, combined with water, and sprayed onto crops to act as an insecticide. As a natural method of nonpesticidal management, A indica acts as an antifeedant, insect repellent, and egg-laying deterrent that protects crops from damage. Studies of A indica have noted effective nonpesticidal management against arthropod pests such as armyworm, termites, and the oriental fruit fly.^7,12,13

Antimalarial Activity—One study indicated that nimbolide, a limonoid from the neem plant, demonstrated antimalarial activity against Plasmodium falciparum. In separate cultures of asexual parasites and mature gametocytes, parasite numbers were less than 50% of the number in control cultures (8.0% vs 8.5% parasitemia, respectively).¹⁴ Thus, the lower parasite numbers indicated by this study highlight the antimalarial utility of nimbolide and neem oil.

Antioxidant and Anti-inflammatory Activity—Neem bark has been reported to have considerable antioxidant activity due to its high phenolic content.^1,15 One study showed that azadirachtin and nimbolide in neem exhibited concentration-dependent antiradical scavenging activity and antioxidant properties.¹⁶

The anti-inflammatory potential for neem may occur via the inhibition of the nuclear factor-κB signaling pathway, which is linked to cancer, inflammation, and apoptosis.¹⁷ It also has been observed that nimbidin within neem extracts—such as leaves, bark, and seed extract—suppresses the function of macrophages and neutrophils relevant to inflammation.¹⁶ Another study indicated neem’s anti-inflammatory activity due to the regulation of proinflammatory enzymes such as cyclooxygenase and lipoxygenase.¹⁸

Safety, Toxicity, and Risks

Ingestion—Although neem is safe to use in the general population, neem oil poisoning has been reported, particularly in young children. Ingesting large quantities of neem has resulted in vomiting, hepatic toxicity, metabolic acidosis, late neurologic sequelae, and encephalopathy in young children.¹⁹ The diagnosis of neem oil poisoning is based on patient history, clinical examination, and imaging findings. Poisoning can manifest as drowsiness, tachypnea, and generalized seizures.²⁰

Topical Application—Topical use of neem appears to be safe if the substance is diluted with other ingredients. However, direct application to the skin is not advised, as it may cause leukoderma and could induce allergic contact dermatitis and other allergic reactions.⁴

Final Thoughts

The use of neem extract for disease prevention and treatment has been prevalent around the world since ancient times. Neem has been documented to possess melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity by means of tyrosinase inhibition, phytochemical production, limonoid expression, and nuclear factor-κB regulation, respectively. However, topical use of neem may trigger a cutaneous response, highlighting the importance of considering a diagnosis of neem oil–induced chemical leukoderma when patients present with a hypopigmented rash and relevant history.

Commonly known as neem or nimba, Azadirachta indica traditionally has been used as an oil or poultice to lighten skin pigment and reduce joint inflammation. Neem is a drought-resistant evergreen tree with thin serrated leaves, white fragrant flowers, and olivelike fruit (Figure 1). This plant is indigenous to India but also is readily found within tropical and semitropical environments throughout the Middle East, Southeast Asia, North Africa, and Australia.

Traditional Uses

For more than 4000 years, neem leaves, bark, fruit, and seeds have been used in food, insecticide, and herbal medicine cross-culturally in Indian Ayurvedic medicine and across Southeast Asia, particularly in Cambodia, Laos, Thailand, Myanmar, and Vietnam.^1-3 Because of its many essential nutrients—oleic acid, palmitic acid, stearic acid, linoleic acid, behenic acid, arachidic acid, and palmitoleic acid—and readily available nature, some ethnic groups include neem in their diet.⁴ Neem commonly is used as a seasoning in soups and rice, eaten as a cooked vegetable, infused into teas and tonics, and pickled with other spices.⁵

All parts of the neem tree—both externally and internally—have been utilized in traditional medicine for the treatment of various diseases and ailments. The flowers have been used to treat eye diseases and dyspepsia, the fruit has been employed as an anthelmintic, the seeds and leaves have been used for malaria treatment and insecticide, the stem bark has been used for the treatment of diarrhea, and the root bark has been used for skin diseases and inflammation.⁶ Neem oil is a yellow-brown bitter substance that often is utilized to treat skin diseases such as psoriasis, eczema, fungal infections, and abscesses.

Case Report—A 77-year-old man presented with a diffuse rash across the lower back. He reported that he had been using topical neem oil to alleviate lower back pain and arthritis for the last 6 months with noted relief and improvement of back pain. After roughly 3 to 4 months of using neem oil, he noted a rash on the lower back, bilateral flanks, and buttocks (Figure 2). The rash was asymptomatic, and he denied any pruritus, scaling, pain, or burning. The patient was referred to dermatology and received a diagnosis of chemical leukoderma secondary to contact with A indica. The patient was advised to stop using the topical neem oil, and the rash was simply monitored, as it was asymptomatic.

Bioactivity

Research has elucidated multiple bioactivity mechanisms of neem, including melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity.^1,7-9 Literature on the diverse phytochemical components of A indica indicate high levels of limonoids, flavonoids, and triterpenoids that are responsible for much of its antioxidant, anti-inflammatory, and insecticide properties.^1,10

Melanogenesis-Inhibitory Activity—To date, neem has been added to a number of cosmetic products used in Ayurvedic medicine. One study of isolated compounds in A indica showed superior inhibitory activities against melanogenesis with minimal toxicity to cells (86.5%–105.1% cell viability). Western blot analysis of samples extracted and isolated from neem root and bark showed melanogenesis-inhibitory activities in B16 melanoma cells through the inhibition of microphthalmia-associated transcription factor expression and decreased expression of tyrosinase, as well as tyrosinase-related proteins 1 and 2, which are largely responsible for melanin synthesis.¹¹ In another study, A indica flowers and their extracted constituents—6-deacetylnimbin and kaempferide—suggest melanogenesis-inhibitory activities in B16 melanoma cells with little to no toxicity to the cells (81.0%–111.7% cell viability).¹ In an evaluationof A indica seed extracts, some of the isolated limonoids and diterpenoids exhibited a marked melanogenesis-inhibitory effect (74%–91% reduction of melanin content) with no toxicity to the cell.⁵ All of these studies indicate that active compounds in neem root, bark, flowers, and seeds may be potential skin-lightening agents.

Toxicity Against Pests—Neem seeds have phytochemicals that convey some insecticidal properties. The seeds often are ground into a powder, combined with water, and sprayed onto crops to act as an insecticide. As a natural method of nonpesticidal management, A indica acts as an antifeedant, insect repellent, and egg-laying deterrent that protects crops from damage. Studies of A indica have noted effective nonpesticidal management against arthropod pests such as armyworm, termites, and the oriental fruit fly.^7,12,13

Antimalarial Activity—One study indicated that nimbolide, a limonoid from the neem plant, demonstrated antimalarial activity against Plasmodium falciparum. In separate cultures of asexual parasites and mature gametocytes, parasite numbers were less than 50% of the number in control cultures (8.0% vs 8.5% parasitemia, respectively).¹⁴ Thus, the lower parasite numbers indicated by this study highlight the antimalarial utility of nimbolide and neem oil.

Antioxidant and Anti-inflammatory Activity—Neem bark has been reported to have considerable antioxidant activity due to its high phenolic content.^1,15 One study showed that azadirachtin and nimbolide in neem exhibited concentration-dependent antiradical scavenging activity and antioxidant properties.¹⁶

The anti-inflammatory potential for neem may occur via the inhibition of the nuclear factor-κB signaling pathway, which is linked to cancer, inflammation, and apoptosis.¹⁷ It also has been observed that nimbidin within neem extracts—such as leaves, bark, and seed extract—suppresses the function of macrophages and neutrophils relevant to inflammation.¹⁶ Another study indicated neem’s anti-inflammatory activity due to the regulation of proinflammatory enzymes such as cyclooxygenase and lipoxygenase.¹⁸

Safety, Toxicity, and Risks

Ingestion—Although neem is safe to use in the general population, neem oil poisoning has been reported, particularly in young children. Ingesting large quantities of neem has resulted in vomiting, hepatic toxicity, metabolic acidosis, late neurologic sequelae, and encephalopathy in young children.¹⁹ The diagnosis of neem oil poisoning is based on patient history, clinical examination, and imaging findings. Poisoning can manifest as drowsiness, tachypnea, and generalized seizures.²⁰

Topical Application—Topical use of neem appears to be safe if the substance is diluted with other ingredients. However, direct application to the skin is not advised, as it may cause leukoderma and could induce allergic contact dermatitis and other allergic reactions.⁴

Final Thoughts

The use of neem extract for disease prevention and treatment has been prevalent around the world since ancient times. Neem has been documented to possess melanogenesis-inhibitory activity, toxicity against pests, antimalarial activity, and antioxidant activity by means of tyrosinase inhibition, phytochemical production, limonoid expression, and nuclear factor-κB regulation, respectively. However, topical use of neem may trigger a cutaneous response, highlighting the importance of considering a diagnosis of neem oil–induced chemical leukoderma when patients present with a hypopigmented rash and relevant history.

Internet platforms have become a common source of medical information for individuals with a broad range of skin conditions including vitiligo. The prevalence of vitiligo among US adults ranges from 0.76% to 1.11%, with approximately 40% of adult cases of vitiligo in the United States remaining undiagnosed.¹ The vitiligo community has become more inquisitive of the relationship between diet and vitiligo, turning to online sources for suggestions on diet modifications that may be beneficial for their condition. Although there is an abundance of online information, few diets or foods have been medically recognized to definitively improve or worsen vitiligo symptoms. We reviewed the top online web pages accessible to the public regarding diet suggestions that affect vitiligo symptoms. We then compared these online results to published peer-reviewed scientific literature.

Methods

Two independent online searches were performed by Researcher 1 (Y.A.) and Researcher 2 (I.M.) using Google Advanced Search. The independent searches were performed by the reviewers in neighboring areas of Chicago, Illinois, using the same Internet browser (Google Chrome). The primary search terms were diet and vitiligo along with the optional additional terms dietary supplement(s), food(s), nutrition, herb(s), or vitamin(s). Our search included any web pages published or updated from January 1, 2010, to December 31, 2021, and originally scribed in the English language. The domains “.com,” “.org,” “.edu,” and “.cc” were included.

From this initial search, Researcher 1 identified 312 web pages and Researcher 2 identified 314 web pages. Each reviewer sorted their respective search results to identify the number of eligible records to be screened. Records were defined as unique web pages that met the search criteria. After removing duplicates, Researcher 1 screened 102 web pages and Researcher 2 screened 76 web pages. Of these records, web pages were excluded if they did not include any diet recommendations for vitiligo patients. Each reviewer independently created a list of eligible records, and the independent lists were then merged for a total of 58 web pages. Among these 58 web pages, there were 24 duplicate records and 3 records that were deemed ineligible for the study due to lack of subject matter relevance. A final total of 31 web pages were included in the data analysis (Figure). Of the 31 records selected, the reviewers jointly evaluated each web page and recorded the diet components that were recommended for individuals with vitiligo to either include or avoid (eTable).

For comparison and support from published scientific literature, a search of PubMed articles indexed for MEDLINE was conducted using the terms diet and vitiligo. Relevant human clinical studies published in the English-language literature were reviewed for content regarding the relationship between diet and vitiligo.

Results

Our online search revealed an abundance of information regarding various dietary modifications suggested to aid in the management of vitiligo symptoms. Most web pages (27/31 [87%]) were not authored by medical professionals or dermatologists. There were 27 diet components mentioned 8 or more times within the 31 total web pages. These diet components were selected for further review via PubMed. Each item was searched on PubMed using the term “[respective diet component] and vitiligo” among all published literature in the English language. Our study focused on summarizing the data on dietary components for which we were able to gather scientific support. These data have been organized into the following categories: vitamins, fruits, omega-3 fatty acids, grains, minerals, vegetables, and nuts.

Vitamins—The online literature recommended inclusion of vitamin supplements, in particular vitamins D and B₁₂, which aligned with published scientific literature.^2,3 Eleven of 31 (35%) web pages recommended vitamin D in vitiligo. A 2010 study analyzing patients with vitiligo vulgaris (N=45) found that 68.9% of the cohort had insufficient (<30 ng/mL) 25-hydroxyvitamin D levels.² A prospective study of 30 individuals found that the use of tacrolimus ointment plus oral vitamin D supplementation was found to be more successful in repigmentation than topical tacrolimus alone.³ Vitamin D dosage ranged from 1500 IU/d if the patient’s serum 25-hydroxyvitamin D levels were less than 20 ng/mL to 3000 IU/d if the serum levels were less than 10 ng/mL for 6 months.

Dairy products are a source of vitamin D.^2,3 Of the web pages that mentioned dairy, a subtle majority (4/7 [57%]) recommended the inclusion of dairy products. Although many web pages did not specify whether oral vitamin D supplementation vs dietary food consumption is preferred, a 2013 controlled study of 16 vitiligo patients who received high doses of vitamin D supplementation with a low-calcium diet found that 4 patients showed 1% to 25% repigmentation, 5 patients showed 26% to 50% repigmentation, and 5 patients showed 51% to 75% repigmentation of the affected areas.⁴

Eleven of 31 (35%) web pages recommended inclusion of vitamin B₁₂ supplementation in vitiligo. A 2-year study with 100 participants showed that supplementation with folic acid and vitamin B₁₂ along with sun exposure yielded more effective repigmentation than either vitamins or sun exposure alone.⁵ An additional hypothesis suggested vitamin B₁₂ may aid in repigmentation through its role in the homocysteine pathway. Although the theory is unproven, it is proposed that inhibition of homocysteine via vitamin B₁₂ or folic acid supplementation may play a role in reducing melanocyte destruction and restoring melanin synthesis.⁶

There were mixed recommendations regarding vitamin C via supplementation and/or eating citrus fruits such as oranges. Although there are limited clinical studies on the use of vitamin C and the treatment of vitiligo, a 6-year prospective study from Madagascar consisting of approximately 300 participants with vitiligo who were treated with a combination of topical corticosteroids, oral vitamin C, and oral vitamin B₁₂ supplementation showed excellent repigmentation (defined by repigmentation of more than 76% of the originally affected area) in 50 participants.⁷

Fruits—Most web pages had mixed recommendations on whether to include or avoid certain fruits. Interestingly, inclusion of mangoes and apricots in the diet were highly recommended (9/31 [29%] and 8/31 [26%], respectively) while fruits such as oranges, lemons, papayas, and grapes were discouraged (10/31 [32%], 8/31 [26%], 6/31 [19%], and 7/31 [23%], respectively). Although some web pages suggested that vitamin C–rich produce including citrus and berries may help to increase melanin formation, others strongly suggested avoiding these fruits. There is limited information on the effects of citrus on vitiligo, but a 2022 study indicated that 5-demethylnobiletin, a flavonoid found in sweet citrus fruits, may stimulate melanin synthesis, which can possibly be beneficial for vitiligo.⁸

Omega-3 Fatty Acids—Seven of 31 (23%) web pages recommended the inclusion of omega-3 fatty acids for their role as antioxidants to improve vitiligo symptoms. Research has indicated a strong association between vitiligo and oxidative stress.⁹ A 2007 controlled clinical trial that included 28 vitiligo patients demonstrated that oral antioxidant supplementation in combination with narrowband UVB phototherapy can significantly decrease vitiligo-associated oxidative stress (P<.05); 8 of 17 (47%) patients in the treatment group saw greater than 75% repigmentation after antioxidant treatment.¹⁰

Grains—Five of 31 (16%) web pages suggested avoiding gluten—a protein naturally found in some grains including wheat, barley, and rye—to improve vitiligo symptoms. A 2021 review suggested that a gluten-free diet may be effective in managing celiac disease, and it is hypothesized that vitiligo may be managed with similar dietary adjustments.¹¹ Studies have shown that celiac disease and vitiligo—both autoimmune conditions—involve IL-2, IL-6, IL-7, and IL-21 in their disease pathways.^12,13 Their shared immunogenic mechanism may account for similar management options.

Upon review, 2 case reports were identified that discussed a relationship between a gluten-free diet and vitiligo symptom improvement. In one report, a 9-year-old child diagnosed with both celiac disease and vitiligo saw intense repigmentation of the skin after adhering to a gluten-free diet for 1 year.¹⁴ Another case study reported a 22-year-old woman with vitiligo whose symptoms improved after 1 month of a gluten-free diet following 2 years of failed treatment with a topical steroid and phototherapy.¹⁵

Seven of 31 (23%) web pages suggested that individuals with vitiligo should include wheat in their diet. There is no published literature discussing the relationship between vitiligo and wheat. Of the 31 web pages reviewed, 10 (32%) suggested including whole grain. There is no relevant scientific evidence or hypotheses describing how whole grains may be beneficial in vitiligo.

Minerals—Eight of 31 (26%) web pages suggested including zinc in the diet to improve vitiligo symptoms. A 2020 study evaluated how different serum levels of zinc in vitiligo patients might be affiliated with interleukin activity. Fifty patients diagnosed with active vitiligo were tested for serum levels of zinc, IL-4, IL-6, and IL-17.¹⁶ The results showed that mean serum levels of zinc were lower in vitiligo patients compared with patients without vitiligo. The study concluded that zinc could possibly be used as a supplement to improve vitiligo, though the dosage needs to be further studied and confirmed.¹⁶

Vegetables—Eleven of 31 (35%) web pages recommended leafy green vegetables and 13 of 31 (42%) recommended spinach for patients with vitiligo. Spinach and other leafy green vegetables are known to be rich in antioxidants, which may have protective effects against reactive oxygen species that are thought to contribute to vitiligo progression.^17,18

Nuts—Walnuts were recommended in 11 of 31 (35%) web pages. Nuts may be beneficial in reducing inflammation and providing protection against oxidative stress.⁹ However, there is no specific scientific literature that supports the inclusion of nuts in the diet to manage vitiligo symptoms.

Comment

With a growing amount of research suggesting that diet modifications may contribute to management of certain skin conditions, vitiligo patients often inquire about foods or supplements that may help improve their condition.¹⁹ Our review highlighted what information was available to the public regarding diet and vitiligo, with preliminary support of the following primary diet components: vitamin D, vitamin B₁₂, zinc, and omega-3 fatty acids. Our review showed no support in the literature for the items that were recommended to avoid. It is important to note that 27 of 31 (87%) web pages from our online search were not authored by medical professionals or dermatologists. Additionally, many web pages suggested conflicting information, making it difficult to draw concrete conclusions about what diet modifications will be beneficial to the vitiligo community. Further controlled clinical trials are warranted due to the lack of formal studies that assess the relationship between diet and vitiligo.

Internet platforms have become a common source of medical information for individuals with a broad range of skin conditions including vitiligo. The prevalence of vitiligo among US adults ranges from 0.76% to 1.11%, with approximately 40% of adult cases of vitiligo in the United States remaining undiagnosed.¹ The vitiligo community has become more inquisitive of the relationship between diet and vitiligo, turning to online sources for suggestions on diet modifications that may be beneficial for their condition. Although there is an abundance of online information, few diets or foods have been medically recognized to definitively improve or worsen vitiligo symptoms. We reviewed the top online web pages accessible to the public regarding diet suggestions that affect vitiligo symptoms. We then compared these online results to published peer-reviewed scientific literature.

Methods

Two independent online searches were performed by Researcher 1 (Y.A.) and Researcher 2 (I.M.) using Google Advanced Search. The independent searches were performed by the reviewers in neighboring areas of Chicago, Illinois, using the same Internet browser (Google Chrome). The primary search terms were diet and vitiligo along with the optional additional terms dietary supplement(s), food(s), nutrition, herb(s), or vitamin(s). Our search included any web pages published or updated from January 1, 2010, to December 31, 2021, and originally scribed in the English language. The domains “.com,” “.org,” “.edu,” and “.cc” were included.

From this initial search, Researcher 1 identified 312 web pages and Researcher 2 identified 314 web pages. Each reviewer sorted their respective search results to identify the number of eligible records to be screened. Records were defined as unique web pages that met the search criteria. After removing duplicates, Researcher 1 screened 102 web pages and Researcher 2 screened 76 web pages. Of these records, web pages were excluded if they did not include any diet recommendations for vitiligo patients. Each reviewer independently created a list of eligible records, and the independent lists were then merged for a total of 58 web pages. Among these 58 web pages, there were 24 duplicate records and 3 records that were deemed ineligible for the study due to lack of subject matter relevance. A final total of 31 web pages were included in the data analysis (Figure). Of the 31 records selected, the reviewers jointly evaluated each web page and recorded the diet components that were recommended for individuals with vitiligo to either include or avoid (eTable).

For comparison and support from published scientific literature, a search of PubMed articles indexed for MEDLINE was conducted using the terms diet and vitiligo. Relevant human clinical studies published in the English-language literature were reviewed for content regarding the relationship between diet and vitiligo.

Results

Our online search revealed an abundance of information regarding various dietary modifications suggested to aid in the management of vitiligo symptoms. Most web pages (27/31 [87%]) were not authored by medical professionals or dermatologists. There were 27 diet components mentioned 8 or more times within the 31 total web pages. These diet components were selected for further review via PubMed. Each item was searched on PubMed using the term “[respective diet component] and vitiligo” among all published literature in the English language. Our study focused on summarizing the data on dietary components for which we were able to gather scientific support. These data have been organized into the following categories: vitamins, fruits, omega-3 fatty acids, grains, minerals, vegetables, and nuts.

Vitamins—The online literature recommended inclusion of vitamin supplements, in particular vitamins D and B₁₂, which aligned with published scientific literature.^2,3 Eleven of 31 (35%) web pages recommended vitamin D in vitiligo. A 2010 study analyzing patients with vitiligo vulgaris (N=45) found that 68.9% of the cohort had insufficient (<30 ng/mL) 25-hydroxyvitamin D levels.² A prospective study of 30 individuals found that the use of tacrolimus ointment plus oral vitamin D supplementation was found to be more successful in repigmentation than topical tacrolimus alone.³ Vitamin D dosage ranged from 1500 IU/d if the patient’s serum 25-hydroxyvitamin D levels were less than 20 ng/mL to 3000 IU/d if the serum levels were less than 10 ng/mL for 6 months.

Dairy products are a source of vitamin D.^2,3 Of the web pages that mentioned dairy, a subtle majority (4/7 [57%]) recommended the inclusion of dairy products. Although many web pages did not specify whether oral vitamin D supplementation vs dietary food consumption is preferred, a 2013 controlled study of 16 vitiligo patients who received high doses of vitamin D supplementation with a low-calcium diet found that 4 patients showed 1% to 25% repigmentation, 5 patients showed 26% to 50% repigmentation, and 5 patients showed 51% to 75% repigmentation of the affected areas.⁴

Eleven of 31 (35%) web pages recommended inclusion of vitamin B₁₂ supplementation in vitiligo. A 2-year study with 100 participants showed that supplementation with folic acid and vitamin B₁₂ along with sun exposure yielded more effective repigmentation than either vitamins or sun exposure alone.⁵ An additional hypothesis suggested vitamin B₁₂ may aid in repigmentation through its role in the homocysteine pathway. Although the theory is unproven, it is proposed that inhibition of homocysteine via vitamin B₁₂ or folic acid supplementation may play a role in reducing melanocyte destruction and restoring melanin synthesis.⁶

There were mixed recommendations regarding vitamin C via supplementation and/or eating citrus fruits such as oranges. Although there are limited clinical studies on the use of vitamin C and the treatment of vitiligo, a 6-year prospective study from Madagascar consisting of approximately 300 participants with vitiligo who were treated with a combination of topical corticosteroids, oral vitamin C, and oral vitamin B₁₂ supplementation showed excellent repigmentation (defined by repigmentation of more than 76% of the originally affected area) in 50 participants.⁷

Fruits—Most web pages had mixed recommendations on whether to include or avoid certain fruits. Interestingly, inclusion of mangoes and apricots in the diet were highly recommended (9/31 [29%] and 8/31 [26%], respectively) while fruits such as oranges, lemons, papayas, and grapes were discouraged (10/31 [32%], 8/31 [26%], 6/31 [19%], and 7/31 [23%], respectively). Although some web pages suggested that vitamin C–rich produce including citrus and berries may help to increase melanin formation, others strongly suggested avoiding these fruits. There is limited information on the effects of citrus on vitiligo, but a 2022 study indicated that 5-demethylnobiletin, a flavonoid found in sweet citrus fruits, may stimulate melanin synthesis, which can possibly be beneficial for vitiligo.⁸

Omega-3 Fatty Acids—Seven of 31 (23%) web pages recommended the inclusion of omega-3 fatty acids for their role as antioxidants to improve vitiligo symptoms. Research has indicated a strong association between vitiligo and oxidative stress.⁹ A 2007 controlled clinical trial that included 28 vitiligo patients demonstrated that oral antioxidant supplementation in combination with narrowband UVB phototherapy can significantly decrease vitiligo-associated oxidative stress (P<.05); 8 of 17 (47%) patients in the treatment group saw greater than 75% repigmentation after antioxidant treatment.¹⁰

Grains—Five of 31 (16%) web pages suggested avoiding gluten—a protein naturally found in some grains including wheat, barley, and rye—to improve vitiligo symptoms. A 2021 review suggested that a gluten-free diet may be effective in managing celiac disease, and it is hypothesized that vitiligo may be managed with similar dietary adjustments.¹¹ Studies have shown that celiac disease and vitiligo—both autoimmune conditions—involve IL-2, IL-6, IL-7, and IL-21 in their disease pathways.^12,13 Their shared immunogenic mechanism may account for similar management options.

Upon review, 2 case reports were identified that discussed a relationship between a gluten-free diet and vitiligo symptom improvement. In one report, a 9-year-old child diagnosed with both celiac disease and vitiligo saw intense repigmentation of the skin after adhering to a gluten-free diet for 1 year.¹⁴ Another case study reported a 22-year-old woman with vitiligo whose symptoms improved after 1 month of a gluten-free diet following 2 years of failed treatment with a topical steroid and phototherapy.¹⁵

Seven of 31 (23%) web pages suggested that individuals with vitiligo should include wheat in their diet. There is no published literature discussing the relationship between vitiligo and wheat. Of the 31 web pages reviewed, 10 (32%) suggested including whole grain. There is no relevant scientific evidence or hypotheses describing how whole grains may be beneficial in vitiligo.

Minerals—Eight of 31 (26%) web pages suggested including zinc in the diet to improve vitiligo symptoms. A 2020 study evaluated how different serum levels of zinc in vitiligo patients might be affiliated with interleukin activity. Fifty patients diagnosed with active vitiligo were tested for serum levels of zinc, IL-4, IL-6, and IL-17.¹⁶ The results showed that mean serum levels of zinc were lower in vitiligo patients compared with patients without vitiligo. The study concluded that zinc could possibly be used as a supplement to improve vitiligo, though the dosage needs to be further studied and confirmed.¹⁶

Vegetables—Eleven of 31 (35%) web pages recommended leafy green vegetables and 13 of 31 (42%) recommended spinach for patients with vitiligo. Spinach and other leafy green vegetables are known to be rich in antioxidants, which may have protective effects against reactive oxygen species that are thought to contribute to vitiligo progression.^17,18

Nuts—Walnuts were recommended in 11 of 31 (35%) web pages. Nuts may be beneficial in reducing inflammation and providing protection against oxidative stress.⁹ However, there is no specific scientific literature that supports the inclusion of nuts in the diet to manage vitiligo symptoms.

Comment

With a growing amount of research suggesting that diet modifications may contribute to management of certain skin conditions, vitiligo patients often inquire about foods or supplements that may help improve their condition.¹⁹ Our review highlighted what information was available to the public regarding diet and vitiligo, with preliminary support of the following primary diet components: vitamin D, vitamin B₁₂, zinc, and omega-3 fatty acids. Our review showed no support in the literature for the items that were recommended to avoid. It is important to note that 27 of 31 (87%) web pages from our online search were not authored by medical professionals or dermatologists. Additionally, many web pages suggested conflicting information, making it difficult to draw concrete conclusions about what diet modifications will be beneficial to the vitiligo community. Further controlled clinical trials are warranted due to the lack of formal studies that assess the relationship between diet and vitiligo.

Internet platforms have become a common source of medical information for individuals with a broad range of skin conditions including vitiligo. The prevalence of vitiligo among US adults ranges from 0.76% to 1.11%, with approximately 40% of adult cases of vitiligo in the United States remaining undiagnosed.¹ The vitiligo community has become more inquisitive of the relationship between diet and vitiligo, turning to online sources for suggestions on diet modifications that may be beneficial for their condition. Although there is an abundance of online information, few diets or foods have been medically recognized to definitively improve or worsen vitiligo symptoms. We reviewed the top online web pages accessible to the public regarding diet suggestions that affect vitiligo symptoms. We then compared these online results to published peer-reviewed scientific literature.

Methods

Two independent online searches were performed by Researcher 1 (Y.A.) and Researcher 2 (I.M.) using Google Advanced Search. The independent searches were performed by the reviewers in neighboring areas of Chicago, Illinois, using the same Internet browser (Google Chrome). The primary search terms were diet and vitiligo along with the optional additional terms dietary supplement(s), food(s), nutrition, herb(s), or vitamin(s). Our search included any web pages published or updated from January 1, 2010, to December 31, 2021, and originally scribed in the English language. The domains “.com,” “.org,” “.edu,” and “.cc” were included.

From this initial search, Researcher 1 identified 312 web pages and Researcher 2 identified 314 web pages. Each reviewer sorted their respective search results to identify the number of eligible records to be screened. Records were defined as unique web pages that met the search criteria. After removing duplicates, Researcher 1 screened 102 web pages and Researcher 2 screened 76 web pages. Of these records, web pages were excluded if they did not include any diet recommendations for vitiligo patients. Each reviewer independently created a list of eligible records, and the independent lists were then merged for a total of 58 web pages. Among these 58 web pages, there were 24 duplicate records and 3 records that were deemed ineligible for the study due to lack of subject matter relevance. A final total of 31 web pages were included in the data analysis (Figure). Of the 31 records selected, the reviewers jointly evaluated each web page and recorded the diet components that were recommended for individuals with vitiligo to either include or avoid (eTable).

For comparison and support from published scientific literature, a search of PubMed articles indexed for MEDLINE was conducted using the terms diet and vitiligo. Relevant human clinical studies published in the English-language literature were reviewed for content regarding the relationship between diet and vitiligo.

Results

Our online search revealed an abundance of information regarding various dietary modifications suggested to aid in the management of vitiligo symptoms. Most web pages (27/31 [87%]) were not authored by medical professionals or dermatologists. There were 27 diet components mentioned 8 or more times within the 31 total web pages. These diet components were selected for further review via PubMed. Each item was searched on PubMed using the term “[respective diet component] and vitiligo” among all published literature in the English language. Our study focused on summarizing the data on dietary components for which we were able to gather scientific support. These data have been organized into the following categories: vitamins, fruits, omega-3 fatty acids, grains, minerals, vegetables, and nuts.

Vitamins—The online literature recommended inclusion of vitamin supplements, in particular vitamins D and B₁₂, which aligned with published scientific literature.^2,3 Eleven of 31 (35%) web pages recommended vitamin D in vitiligo. A 2010 study analyzing patients with vitiligo vulgaris (N=45) found that 68.9% of the cohort had insufficient (<30 ng/mL) 25-hydroxyvitamin D levels.² A prospective study of 30 individuals found that the use of tacrolimus ointment plus oral vitamin D supplementation was found to be more successful in repigmentation than topical tacrolimus alone.³ Vitamin D dosage ranged from 1500 IU/d if the patient’s serum 25-hydroxyvitamin D levels were less than 20 ng/mL to 3000 IU/d if the serum levels were less than 10 ng/mL for 6 months.

Dairy products are a source of vitamin D.^2,3 Of the web pages that mentioned dairy, a subtle majority (4/7 [57%]) recommended the inclusion of dairy products. Although many web pages did not specify whether oral vitamin D supplementation vs dietary food consumption is preferred, a 2013 controlled study of 16 vitiligo patients who received high doses of vitamin D supplementation with a low-calcium diet found that 4 patients showed 1% to 25% repigmentation, 5 patients showed 26% to 50% repigmentation, and 5 patients showed 51% to 75% repigmentation of the affected areas.⁴

Eleven of 31 (35%) web pages recommended inclusion of vitamin B₁₂ supplementation in vitiligo. A 2-year study with 100 participants showed that supplementation with folic acid and vitamin B₁₂ along with sun exposure yielded more effective repigmentation than either vitamins or sun exposure alone.⁵ An additional hypothesis suggested vitamin B₁₂ may aid in repigmentation through its role in the homocysteine pathway. Although the theory is unproven, it is proposed that inhibition of homocysteine via vitamin B₁₂ or folic acid supplementation may play a role in reducing melanocyte destruction and restoring melanin synthesis.⁶

There were mixed recommendations regarding vitamin C via supplementation and/or eating citrus fruits such as oranges. Although there are limited clinical studies on the use of vitamin C and the treatment of vitiligo, a 6-year prospective study from Madagascar consisting of approximately 300 participants with vitiligo who were treated with a combination of topical corticosteroids, oral vitamin C, and oral vitamin B₁₂ supplementation showed excellent repigmentation (defined by repigmentation of more than 76% of the originally affected area) in 50 participants.⁷

Fruits—Most web pages had mixed recommendations on whether to include or avoid certain fruits. Interestingly, inclusion of mangoes and apricots in the diet were highly recommended (9/31 [29%] and 8/31 [26%], respectively) while fruits such as oranges, lemons, papayas, and grapes were discouraged (10/31 [32%], 8/31 [26%], 6/31 [19%], and 7/31 [23%], respectively). Although some web pages suggested that vitamin C–rich produce including citrus and berries may help to increase melanin formation, others strongly suggested avoiding these fruits. There is limited information on the effects of citrus on vitiligo, but a 2022 study indicated that 5-demethylnobiletin, a flavonoid found in sweet citrus fruits, may stimulate melanin synthesis, which can possibly be beneficial for vitiligo.⁸

Omega-3 Fatty Acids—Seven of 31 (23%) web pages recommended the inclusion of omega-3 fatty acids for their role as antioxidants to improve vitiligo symptoms. Research has indicated a strong association between vitiligo and oxidative stress.⁹ A 2007 controlled clinical trial that included 28 vitiligo patients demonstrated that oral antioxidant supplementation in combination with narrowband UVB phototherapy can significantly decrease vitiligo-associated oxidative stress (P<.05); 8 of 17 (47%) patients in the treatment group saw greater than 75% repigmentation after antioxidant treatment.¹⁰

Grains—Five of 31 (16%) web pages suggested avoiding gluten—a protein naturally found in some grains including wheat, barley, and rye—to improve vitiligo symptoms. A 2021 review suggested that a gluten-free diet may be effective in managing celiac disease, and it is hypothesized that vitiligo may be managed with similar dietary adjustments.¹¹ Studies have shown that celiac disease and vitiligo—both autoimmune conditions—involve IL-2, IL-6, IL-7, and IL-21 in their disease pathways.^12,13 Their shared immunogenic mechanism may account for similar management options.

Upon review, 2 case reports were identified that discussed a relationship between a gluten-free diet and vitiligo symptom improvement. In one report, a 9-year-old child diagnosed with both celiac disease and vitiligo saw intense repigmentation of the skin after adhering to a gluten-free diet for 1 year.¹⁴ Another case study reported a 22-year-old woman with vitiligo whose symptoms improved after 1 month of a gluten-free diet following 2 years of failed treatment with a topical steroid and phototherapy.¹⁵

Seven of 31 (23%) web pages suggested that individuals with vitiligo should include wheat in their diet. There is no published literature discussing the relationship between vitiligo and wheat. Of the 31 web pages reviewed, 10 (32%) suggested including whole grain. There is no relevant scientific evidence or hypotheses describing how whole grains may be beneficial in vitiligo.

Minerals—Eight of 31 (26%) web pages suggested including zinc in the diet to improve vitiligo symptoms. A 2020 study evaluated how different serum levels of zinc in vitiligo patients might be affiliated with interleukin activity. Fifty patients diagnosed with active vitiligo were tested for serum levels of zinc, IL-4, IL-6, and IL-17.¹⁶ The results showed that mean serum levels of zinc were lower in vitiligo patients compared with patients without vitiligo. The study concluded that zinc could possibly be used as a supplement to improve vitiligo, though the dosage needs to be further studied and confirmed.¹⁶

Vegetables—Eleven of 31 (35%) web pages recommended leafy green vegetables and 13 of 31 (42%) recommended spinach for patients with vitiligo. Spinach and other leafy green vegetables are known to be rich in antioxidants, which may have protective effects against reactive oxygen species that are thought to contribute to vitiligo progression.^17,18

Nuts—Walnuts were recommended in 11 of 31 (35%) web pages. Nuts may be beneficial in reducing inflammation and providing protection against oxidative stress.⁹ However, there is no specific scientific literature that supports the inclusion of nuts in the diet to manage vitiligo symptoms.

Comment

With a growing amount of research suggesting that diet modifications may contribute to management of certain skin conditions, vitiligo patients often inquire about foods or supplements that may help improve their condition.¹⁹ Our review highlighted what information was available to the public regarding diet and vitiligo, with preliminary support of the following primary diet components: vitamin D, vitamin B₁₂, zinc, and omega-3 fatty acids. Our review showed no support in the literature for the items that were recommended to avoid. It is important to note that 27 of 31 (87%) web pages from our online search were not authored by medical professionals or dermatologists. Additionally, many web pages suggested conflicting information, making it difficult to draw concrete conclusions about what diet modifications will be beneficial to the vitiligo community. Further controlled clinical trials are warranted due to the lack of formal studies that assess the relationship between diet and vitiligo.

Medication-induced telogen effluvium (TE) is a nonscarring alopecia that typically is reversible. Appropriate management requires identification of the underlying trigger and cessation of potential culprit medications. In part 2 of this series, we review anticoagulant and antihypertensive medications as potential contributors to TE.

Anticoagulants

Anticoagulants target various parts of the coagulation cascade to prevent clot formation in patients with conditions that increase their risk for thromboembolic events. Common indications for initiating anticoagulant therapy include atrial fibrillation,¹ venous thromboembolism,² acute myocardial infarction,³ malignancy,⁴ and hypercoagulable states.⁵ Traditional anticoagulants include heparin and warfarin. Heparin is a glycosaminoglycan that exerts its anticoagulant effects through binding with antithrombin, greatly increasing its inactivation of thrombin and factor Xa of the coagulation cascade.⁶ Warfarin is a coumarin derivative that inhibits activation of vitamin K, subsequently limiting the function of vitamin K–dependent factors II, VII, IX, and X.^7,8 Watras et al⁹ noted that heparin and warfarin were implicated in alopecia as their clinical use became widespread throughout the mid-20th century. Onset of alopecia following the use of heparin or warfarin was reported at 3 weeks to 3 months following medication initiation, with most cases clinically consistent with TE.⁹ Heparin and warfarin both have alopecia reported as a potential adverse effect in their structured product labeling documents.^10,11

Heparin is further classified into unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH); the latter is a heterogeneous group of medications derived from chemical or enzymatic depolymerization of UFH.¹² In contrast to UFH, LMWH exerts its anticoagulant effects through inactivation of factor Xa without the ability to bind thrombin.¹² An animal study using anagen-induced mice demonstrated that intraperitoneal administration of heparin inhibited the development of anagen follicles, while in vitro studies showed that the addition of heparin inhibited mouse dermal papilla cell proliferation.¹³ Other animal and in vitro studies have examined the inhibitory effects of heparin on signaling pathways in tumor lymphangiogenesis, including the vascular endothelial growth factor C/vascular endothelial growth factor receptor 3 axis.^14,15 Clinically, it has been demonstrated that heparin, especially LMWHs, may be associated with a survival benefit among certain cancer patients,^16,17 with the impact of LMWHs attributed to antimitotic and antimetastatic effects of heparin on tumor growth.¹⁴ It is hypothesized that such antiangiogenic and antimitotic effects also are involved in the pathomechanisms of heparin-induced alopecia.¹⁸

More recently, the use of direct oral anticoagulants (DOACs) such as dabigatran, rivaroxaban, and apixaban has increased due to their more favorable adverse-effect profile and minimal monitoring requirements. Bonaldo et al¹⁹ conducted an analysis of reports submitted to the World Health Organization’s VigiBase database of alopecia associated with DOACs until May 2, 2018. They found 1316 nonduplicate DOAC-induced cases of alopecia, with rivaroxaban as the most reported drug associated with alopecia development (58.8% [774/1316]). Only 4 cases demonstrated alopecia with DOAC rechallenge, suggesting onset of alopecia may have been unrelated to DOAC use or caused by a different trigger. Among 243 cases with a documented time to onset of alopecia, the median was 28 days, with an interquartile range of 63 days. Because TE most commonly occurs 3 to 4 months after the inciting event or medication trigger, there is little evidence to suggest DOACs as the cause of TE, and the observed cases of alopecia may be attributable to another preceding medical event and/or medication exposure.¹⁹ More studies are needed to examine the impact of anticoagulant medications on the hair cycle.

Antihypertensives

Hypertension is a modifiable risk factor for several ­cardiovascular diseases.²⁰ According to the 2019 American College of Cardiology/American Heart Association Guideline on the Primary Prevention of Cardiovascular Disease,²¹ first-line medications include thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor ­blockers (ARBs).

Angiotensin-converting enzyme inhibitors exert their antihypertensive effects by reducing conversion of angiotensin I to angiotensin II, thereby limiting the downstream effects of vasoconstriction as well as sodium and water retention. Given the proven mortality benefit of ACE inhibition in patients with congestive heart failure, ACE inhibitors are used as first-line therapy in these patients.^22,23 Alopecia associated with ACE inhibitors is rare and limited to case reports following their introduction and approval in 1981.^24-28 In one case, a woman in her 60s with congestive heart failure initiated captopril with development of an erythematous pruritic rash on the extremities and diffuse scalp hair loss 2 months later; spontaneous hair growth resumed 1 month following captopril discontinuation.²⁵ In this case, the hair loss may be secondary to the drug eruption rather than true medication-induced TE. Initiation of enalapril in a woman in her 30s with hypertension was associated with diffuse scalp alopecia 4 weeks later that resolved with cessation of the suspected culprit, enalapril; rechallenge with enalapril several months later reproduced the hair loss.²⁷ Given limited reports of ACE inhibitor–associated hair loss relative to their pervasive use, a direct causal role between ACE inhibition and TE is unlikely, or it has not been rigorously identified. The structured product labeling for captopril includes alopecia in its list of adverse effects reported in approximately 0.5% to 2% of patients but did not appear at increased frequency compared to placebo or other treatments used in controlled trials.²⁹ Alternative inciting causes of alopecia in patients prescribed ACE inhibitors may include use of other medications, hospitalization, or metabolic derangements related to their underlying cardiac disease.

Although not indicated as a primary treatment for hypertension, β-blockers have US Food and Drug Administration approval for the treatment of certain arrhythmias, hypertension, heart failure, myocardial infarction, hyperthyroidism, and other conditions.³⁰β-Blockers are competitive antagonists of β-adrenergic receptors that limit the production of intracellular cyclic adenosine monophosphate, but the mechanism of β-blockers as antihypertensives is unclear.³¹ Evidence supporting the role of β-adrenergic antagonists in TE is limited to case reports. Widespread alopecia across the scalp and arms was noted in a man in his 30s several months after starting propranolol.³² Biopsy of an affected area of the scalp demonstrated an increased number of telogen follicles with no other abnormalities. Near-complete resolution of alopecia was seen 4 months following cessation of propranolol, which recurred within 4 weeks of rechallenge.³² Although the histopathologic features are compatible with TE, the loss of body hair and rapid recurrence within 4 weeks of rechallenge are atypical for TE. As such, the use of propranolol and the reported alopecia may be coincidental or evidence of an atypical drug reaction distinct from medication-induced TE. Only a handful of other case reports have been published describing TE in patients treated with β-blockers, including metoprolol and propranolol.^33,34 Alopecia has been reported with the use of carvedilol in up to 0.1% of participants.³⁵ Although cases have been reported, TE appears to be an uncommon occurrence following β-blocker therapy.

Minoxidil—Oral minoxidil originally was approved for use in patients with resistant hypertension, defined as blood pressure elevated above goal despite concurrent use of the maximum dose of 3 classes of antihypertensives.³⁶ Unlike other antihypertensive medications, minoxidil appears to cause reversible hypertrichosis that affects nearly all patients using oral minoxidil for longer than 1 month.³⁷ This common adverse effect was a desired outcome in patients affected by hair loss, and a topical formulation of minoxidil was approved for androgenetic alopecia in men and women in 1988 and 1991, respectively.³⁸ Since its approval, topical minoxidil has been commonly prescribed in the treatment of several types of alopecia, though evidence of its efficacy in the treatment of TE is limited.^39,40 Low-dose oral minoxidil also has been reported to aid hair growth in androgenetic alopecia and TE.⁴¹ Taken orally, minoxidil is converted by sulfotransferases in the liver to minoxidil sulfate, which causes opening of plasma membrane adenosine ­triphosphate–sensitive potassium channels.^42-44 The subsequent membrane hyperpolarization reduces calcium ion influx, which also reduces cell excitability, and inhibits contraction in vascular smooth muscle cells, which results in the arteriolar vasodilatory and antihypertensive effects of minoxidil.^43,45 The potassium channel–opening effects of minoxidil may underly its hair growth stimulatory action. Unrelated potassium channel openers such as diazoxide and pinacidil also cause hypertrichosis.^46-48 An animal study showed that topical minoxidil, cromakalim (potassium channel opener), and P1075 (pinacidil analog) applied daily to the scalps of balding stump-tailed macaques led to significant increases in hair weight over a 20-week treatment period compared with the vehicle control group (P<.05 for minoxidil 100 mM and 250 mM, cromakalim 100 mM, and P1075 100 mM and 250 mM).⁵⁰ For minoxidil, this effect on hair growth appears to be dose dependent, as cumulative hair weights for the study period were significantly greater in the 250-mM concentration compared with 100-mM minoxidil (P<.05).⁴⁹ The potassium channel–opening activity of minoxidil may induce stimulation of microcirculation around hair follicles conducive to hair growth.⁵⁰ Other proposed mechanisms for hair growth with minoxidil include effects on keratinocyte and fibroblast cell proliferation,^51-53 collagen synthesis,^52,54 and prostaglandin activity.^44,55

Final Thoughts

Medication-induced TE is an undesired adverse effect of many commonly used medications, including retinoids, azole antifungals, mood stabilizers, anticoagulants, and antihypertensives. In part 1⁵⁶ of this 2-part series, we reviewed the existing literature on hair loss from retinoids, antifungals, and psychotropic medications. Herein, we focused on anticoagulant and antihypertensive medications as potential culprits of TE. Heparin and its derivatives have been associated with development of diffuse alopecia weeks to months after the start of treatment. Alopecia associated with ACE inhibitors and β-blockers has been described only in case reports, suggesting that they may be unlikely causes of TE. In contrast, minoxidil is an antihypertensive that can result in hypertrichosis and is used in the treatment of androgenetic alopecia. It should not be assumed that medications that share an indication or are part of the same medication class would similarly induce TE. The development of diffuse nonscarring alopecia should prompt suspicion for TE and thorough investigation of medications initiated 1 to 6 months prior to onset of clinically apparent alopecia. Suspected culprit medications should be carefully assessed for their likelihood of inducing TE.

Medication-induced telogen effluvium (TE) is a nonscarring alopecia that typically is reversible. Appropriate management requires identification of the underlying trigger and cessation of potential culprit medications. In part 2 of this series, we review anticoagulant and antihypertensive medications as potential contributors to TE.

Anticoagulants

Anticoagulants target various parts of the coagulation cascade to prevent clot formation in patients with conditions that increase their risk for thromboembolic events. Common indications for initiating anticoagulant therapy include atrial fibrillation,¹ venous thromboembolism,² acute myocardial infarction,³ malignancy,⁴ and hypercoagulable states.⁵ Traditional anticoagulants include heparin and warfarin. Heparin is a glycosaminoglycan that exerts its anticoagulant effects through binding with antithrombin, greatly increasing its inactivation of thrombin and factor Xa of the coagulation cascade.⁶ Warfarin is a coumarin derivative that inhibits activation of vitamin K, subsequently limiting the function of vitamin K–dependent factors II, VII, IX, and X.^7,8 Watras et al⁹ noted that heparin and warfarin were implicated in alopecia as their clinical use became widespread throughout the mid-20th century. Onset of alopecia following the use of heparin or warfarin was reported at 3 weeks to 3 months following medication initiation, with most cases clinically consistent with TE.⁹ Heparin and warfarin both have alopecia reported as a potential adverse effect in their structured product labeling documents.^10,11

Heparin is further classified into unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH); the latter is a heterogeneous group of medications derived from chemical or enzymatic depolymerization of UFH.¹² In contrast to UFH, LMWH exerts its anticoagulant effects through inactivation of factor Xa without the ability to bind thrombin.¹² An animal study using anagen-induced mice demonstrated that intraperitoneal administration of heparin inhibited the development of anagen follicles, while in vitro studies showed that the addition of heparin inhibited mouse dermal papilla cell proliferation.¹³ Other animal and in vitro studies have examined the inhibitory effects of heparin on signaling pathways in tumor lymphangiogenesis, including the vascular endothelial growth factor C/vascular endothelial growth factor receptor 3 axis.^14,15 Clinically, it has been demonstrated that heparin, especially LMWHs, may be associated with a survival benefit among certain cancer patients,^16,17 with the impact of LMWHs attributed to antimitotic and antimetastatic effects of heparin on tumor growth.¹⁴ It is hypothesized that such antiangiogenic and antimitotic effects also are involved in the pathomechanisms of heparin-induced alopecia.¹⁸

More recently, the use of direct oral anticoagulants (DOACs) such as dabigatran, rivaroxaban, and apixaban has increased due to their more favorable adverse-effect profile and minimal monitoring requirements. Bonaldo et al¹⁹ conducted an analysis of reports submitted to the World Health Organization’s VigiBase database of alopecia associated with DOACs until May 2, 2018. They found 1316 nonduplicate DOAC-induced cases of alopecia, with rivaroxaban as the most reported drug associated with alopecia development (58.8% [774/1316]). Only 4 cases demonstrated alopecia with DOAC rechallenge, suggesting onset of alopecia may have been unrelated to DOAC use or caused by a different trigger. Among 243 cases with a documented time to onset of alopecia, the median was 28 days, with an interquartile range of 63 days. Because TE most commonly occurs 3 to 4 months after the inciting event or medication trigger, there is little evidence to suggest DOACs as the cause of TE, and the observed cases of alopecia may be attributable to another preceding medical event and/or medication exposure.¹⁹ More studies are needed to examine the impact of anticoagulant medications on the hair cycle.

Antihypertensives

Hypertension is a modifiable risk factor for several ­cardiovascular diseases.²⁰ According to the 2019 American College of Cardiology/American Heart Association Guideline on the Primary Prevention of Cardiovascular Disease,²¹ first-line medications include thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor ­blockers (ARBs).

Angiotensin-converting enzyme inhibitors exert their antihypertensive effects by reducing conversion of angiotensin I to angiotensin II, thereby limiting the downstream effects of vasoconstriction as well as sodium and water retention. Given the proven mortality benefit of ACE inhibition in patients with congestive heart failure, ACE inhibitors are used as first-line therapy in these patients.^22,23 Alopecia associated with ACE inhibitors is rare and limited to case reports following their introduction and approval in 1981.^24-28 In one case, a woman in her 60s with congestive heart failure initiated captopril with development of an erythematous pruritic rash on the extremities and diffuse scalp hair loss 2 months later; spontaneous hair growth resumed 1 month following captopril discontinuation.²⁵ In this case, the hair loss may be secondary to the drug eruption rather than true medication-induced TE. Initiation of enalapril in a woman in her 30s with hypertension was associated with diffuse scalp alopecia 4 weeks later that resolved with cessation of the suspected culprit, enalapril; rechallenge with enalapril several months later reproduced the hair loss.²⁷ Given limited reports of ACE inhibitor–associated hair loss relative to their pervasive use, a direct causal role between ACE inhibition and TE is unlikely, or it has not been rigorously identified. The structured product labeling for captopril includes alopecia in its list of adverse effects reported in approximately 0.5% to 2% of patients but did not appear at increased frequency compared to placebo or other treatments used in controlled trials.²⁹ Alternative inciting causes of alopecia in patients prescribed ACE inhibitors may include use of other medications, hospitalization, or metabolic derangements related to their underlying cardiac disease.

Although not indicated as a primary treatment for hypertension, β-blockers have US Food and Drug Administration approval for the treatment of certain arrhythmias, hypertension, heart failure, myocardial infarction, hyperthyroidism, and other conditions.³⁰β-Blockers are competitive antagonists of β-adrenergic receptors that limit the production of intracellular cyclic adenosine monophosphate, but the mechanism of β-blockers as antihypertensives is unclear.³¹ Evidence supporting the role of β-adrenergic antagonists in TE is limited to case reports. Widespread alopecia across the scalp and arms was noted in a man in his 30s several months after starting propranolol.³² Biopsy of an affected area of the scalp demonstrated an increased number of telogen follicles with no other abnormalities. Near-complete resolution of alopecia was seen 4 months following cessation of propranolol, which recurred within 4 weeks of rechallenge.³² Although the histopathologic features are compatible with TE, the loss of body hair and rapid recurrence within 4 weeks of rechallenge are atypical for TE. As such, the use of propranolol and the reported alopecia may be coincidental or evidence of an atypical drug reaction distinct from medication-induced TE. Only a handful of other case reports have been published describing TE in patients treated with β-blockers, including metoprolol and propranolol.^33,34 Alopecia has been reported with the use of carvedilol in up to 0.1% of participants.³⁵ Although cases have been reported, TE appears to be an uncommon occurrence following β-blocker therapy.

Minoxidil—Oral minoxidil originally was approved for use in patients with resistant hypertension, defined as blood pressure elevated above goal despite concurrent use of the maximum dose of 3 classes of antihypertensives.³⁶ Unlike other antihypertensive medications, minoxidil appears to cause reversible hypertrichosis that affects nearly all patients using oral minoxidil for longer than 1 month.³⁷ This common adverse effect was a desired outcome in patients affected by hair loss, and a topical formulation of minoxidil was approved for androgenetic alopecia in men and women in 1988 and 1991, respectively.³⁸ Since its approval, topical minoxidil has been commonly prescribed in the treatment of several types of alopecia, though evidence of its efficacy in the treatment of TE is limited.^39,40 Low-dose oral minoxidil also has been reported to aid hair growth in androgenetic alopecia and TE.⁴¹ Taken orally, minoxidil is converted by sulfotransferases in the liver to minoxidil sulfate, which causes opening of plasma membrane adenosine ­triphosphate–sensitive potassium channels.^42-44 The subsequent membrane hyperpolarization reduces calcium ion influx, which also reduces cell excitability, and inhibits contraction in vascular smooth muscle cells, which results in the arteriolar vasodilatory and antihypertensive effects of minoxidil.^43,45 The potassium channel–opening effects of minoxidil may underly its hair growth stimulatory action. Unrelated potassium channel openers such as diazoxide and pinacidil also cause hypertrichosis.^46-48 An animal study showed that topical minoxidil, cromakalim (potassium channel opener), and P1075 (pinacidil analog) applied daily to the scalps of balding stump-tailed macaques led to significant increases in hair weight over a 20-week treatment period compared with the vehicle control group (P<.05 for minoxidil 100 mM and 250 mM, cromakalim 100 mM, and P1075 100 mM and 250 mM).⁵⁰ For minoxidil, this effect on hair growth appears to be dose dependent, as cumulative hair weights for the study period were significantly greater in the 250-mM concentration compared with 100-mM minoxidil (P<.05).⁴⁹ The potassium channel–opening activity of minoxidil may induce stimulation of microcirculation around hair follicles conducive to hair growth.⁵⁰ Other proposed mechanisms for hair growth with minoxidil include effects on keratinocyte and fibroblast cell proliferation,^51-53 collagen synthesis,^52,54 and prostaglandin activity.^44,55

Final Thoughts

Medication-induced TE is an undesired adverse effect of many commonly used medications, including retinoids, azole antifungals, mood stabilizers, anticoagulants, and antihypertensives. In part 1⁵⁶ of this 2-part series, we reviewed the existing literature on hair loss from retinoids, antifungals, and psychotropic medications. Herein, we focused on anticoagulant and antihypertensive medications as potential culprits of TE. Heparin and its derivatives have been associated with development of diffuse alopecia weeks to months after the start of treatment. Alopecia associated with ACE inhibitors and β-blockers has been described only in case reports, suggesting that they may be unlikely causes of TE. In contrast, minoxidil is an antihypertensive that can result in hypertrichosis and is used in the treatment of androgenetic alopecia. It should not be assumed that medications that share an indication or are part of the same medication class would similarly induce TE. The development of diffuse nonscarring alopecia should prompt suspicion for TE and thorough investigation of medications initiated 1 to 6 months prior to onset of clinically apparent alopecia. Suspected culprit medications should be carefully assessed for their likelihood of inducing TE.

Medication-induced telogen effluvium (TE) is a nonscarring alopecia that typically is reversible. Appropriate management requires identification of the underlying trigger and cessation of potential culprit medications. In part 2 of this series, we review anticoagulant and antihypertensive medications as potential contributors to TE.

Anticoagulants

Anticoagulants target various parts of the coagulation cascade to prevent clot formation in patients with conditions that increase their risk for thromboembolic events. Common indications for initiating anticoagulant therapy include atrial fibrillation,¹ venous thromboembolism,² acute myocardial infarction,³ malignancy,⁴ and hypercoagulable states.⁵ Traditional anticoagulants include heparin and warfarin. Heparin is a glycosaminoglycan that exerts its anticoagulant effects through binding with antithrombin, greatly increasing its inactivation of thrombin and factor Xa of the coagulation cascade.⁶ Warfarin is a coumarin derivative that inhibits activation of vitamin K, subsequently limiting the function of vitamin K–dependent factors II, VII, IX, and X.^7,8 Watras et al⁹ noted that heparin and warfarin were implicated in alopecia as their clinical use became widespread throughout the mid-20th century. Onset of alopecia following the use of heparin or warfarin was reported at 3 weeks to 3 months following medication initiation, with most cases clinically consistent with TE.⁹ Heparin and warfarin both have alopecia reported as a potential adverse effect in their structured product labeling documents.^10,11

Heparin is further classified into unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH); the latter is a heterogeneous group of medications derived from chemical or enzymatic depolymerization of UFH.¹² In contrast to UFH, LMWH exerts its anticoagulant effects through inactivation of factor Xa without the ability to bind thrombin.¹² An animal study using anagen-induced mice demonstrated that intraperitoneal administration of heparin inhibited the development of anagen follicles, while in vitro studies showed that the addition of heparin inhibited mouse dermal papilla cell proliferation.¹³ Other animal and in vitro studies have examined the inhibitory effects of heparin on signaling pathways in tumor lymphangiogenesis, including the vascular endothelial growth factor C/vascular endothelial growth factor receptor 3 axis.^14,15 Clinically, it has been demonstrated that heparin, especially LMWHs, may be associated with a survival benefit among certain cancer patients,^16,17 with the impact of LMWHs attributed to antimitotic and antimetastatic effects of heparin on tumor growth.¹⁴ It is hypothesized that such antiangiogenic and antimitotic effects also are involved in the pathomechanisms of heparin-induced alopecia.¹⁸

More recently, the use of direct oral anticoagulants (DOACs) such as dabigatran, rivaroxaban, and apixaban has increased due to their more favorable adverse-effect profile and minimal monitoring requirements. Bonaldo et al¹⁹ conducted an analysis of reports submitted to the World Health Organization’s VigiBase database of alopecia associated with DOACs until May 2, 2018. They found 1316 nonduplicate DOAC-induced cases of alopecia, with rivaroxaban as the most reported drug associated with alopecia development (58.8% [774/1316]). Only 4 cases demonstrated alopecia with DOAC rechallenge, suggesting onset of alopecia may have been unrelated to DOAC use or caused by a different trigger. Among 243 cases with a documented time to onset of alopecia, the median was 28 days, with an interquartile range of 63 days. Because TE most commonly occurs 3 to 4 months after the inciting event or medication trigger, there is little evidence to suggest DOACs as the cause of TE, and the observed cases of alopecia may be attributable to another preceding medical event and/or medication exposure.¹⁹ More studies are needed to examine the impact of anticoagulant medications on the hair cycle.

Antihypertensives

Hypertension is a modifiable risk factor for several ­cardiovascular diseases.²⁰ According to the 2019 American College of Cardiology/American Heart Association Guideline on the Primary Prevention of Cardiovascular Disease,²¹ first-line medications include thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor ­blockers (ARBs).

Angiotensin-converting enzyme inhibitors exert their antihypertensive effects by reducing conversion of angiotensin I to angiotensin II, thereby limiting the downstream effects of vasoconstriction as well as sodium and water retention. Given the proven mortality benefit of ACE inhibition in patients with congestive heart failure, ACE inhibitors are used as first-line therapy in these patients.^22,23 Alopecia associated with ACE inhibitors is rare and limited to case reports following their introduction and approval in 1981.^24-28 In one case, a woman in her 60s with congestive heart failure initiated captopril with development of an erythematous pruritic rash on the extremities and diffuse scalp hair loss 2 months later; spontaneous hair growth resumed 1 month following captopril discontinuation.²⁵ In this case, the hair loss may be secondary to the drug eruption rather than true medication-induced TE. Initiation of enalapril in a woman in her 30s with hypertension was associated with diffuse scalp alopecia 4 weeks later that resolved with cessation of the suspected culprit, enalapril; rechallenge with enalapril several months later reproduced the hair loss.²⁷ Given limited reports of ACE inhibitor–associated hair loss relative to their pervasive use, a direct causal role between ACE inhibition and TE is unlikely, or it has not been rigorously identified. The structured product labeling for captopril includes alopecia in its list of adverse effects reported in approximately 0.5% to 2% of patients but did not appear at increased frequency compared to placebo or other treatments used in controlled trials.²⁹ Alternative inciting causes of alopecia in patients prescribed ACE inhibitors may include use of other medications, hospitalization, or metabolic derangements related to their underlying cardiac disease.

Although not indicated as a primary treatment for hypertension, β-blockers have US Food and Drug Administration approval for the treatment of certain arrhythmias, hypertension, heart failure, myocardial infarction, hyperthyroidism, and other conditions.³⁰β-Blockers are competitive antagonists of β-adrenergic receptors that limit the production of intracellular cyclic adenosine monophosphate, but the mechanism of β-blockers as antihypertensives is unclear.³¹ Evidence supporting the role of β-adrenergic antagonists in TE is limited to case reports. Widespread alopecia across the scalp and arms was noted in a man in his 30s several months after starting propranolol.³² Biopsy of an affected area of the scalp demonstrated an increased number of telogen follicles with no other abnormalities. Near-complete resolution of alopecia was seen 4 months following cessation of propranolol, which recurred within 4 weeks of rechallenge.³² Although the histopathologic features are compatible with TE, the loss of body hair and rapid recurrence within 4 weeks of rechallenge are atypical for TE. As such, the use of propranolol and the reported alopecia may be coincidental or evidence of an atypical drug reaction distinct from medication-induced TE. Only a handful of other case reports have been published describing TE in patients treated with β-blockers, including metoprolol and propranolol.^33,34 Alopecia has been reported with the use of carvedilol in up to 0.1% of participants.³⁵ Although cases have been reported, TE appears to be an uncommon occurrence following β-blocker therapy.

Minoxidil—Oral minoxidil originally was approved for use in patients with resistant hypertension, defined as blood pressure elevated above goal despite concurrent use of the maximum dose of 3 classes of antihypertensives.³⁶ Unlike other antihypertensive medications, minoxidil appears to cause reversible hypertrichosis that affects nearly all patients using oral minoxidil for longer than 1 month.³⁷ This common adverse effect was a desired outcome in patients affected by hair loss, and a topical formulation of minoxidil was approved for androgenetic alopecia in men and women in 1988 and 1991, respectively.³⁸ Since its approval, topical minoxidil has been commonly prescribed in the treatment of several types of alopecia, though evidence of its efficacy in the treatment of TE is limited.^39,40 Low-dose oral minoxidil also has been reported to aid hair growth in androgenetic alopecia and TE.⁴¹ Taken orally, minoxidil is converted by sulfotransferases in the liver to minoxidil sulfate, which causes opening of plasma membrane adenosine ­triphosphate–sensitive potassium channels.^42-44 The subsequent membrane hyperpolarization reduces calcium ion influx, which also reduces cell excitability, and inhibits contraction in vascular smooth muscle cells, which results in the arteriolar vasodilatory and antihypertensive effects of minoxidil.^43,45 The potassium channel–opening effects of minoxidil may underly its hair growth stimulatory action. Unrelated potassium channel openers such as diazoxide and pinacidil also cause hypertrichosis.^46-48 An animal study showed that topical minoxidil, cromakalim (potassium channel opener), and P1075 (pinacidil analog) applied daily to the scalps of balding stump-tailed macaques led to significant increases in hair weight over a 20-week treatment period compared with the vehicle control group (P<.05 for minoxidil 100 mM and 250 mM, cromakalim 100 mM, and P1075 100 mM and 250 mM).⁵⁰ For minoxidil, this effect on hair growth appears to be dose dependent, as cumulative hair weights for the study period were significantly greater in the 250-mM concentration compared with 100-mM minoxidil (P<.05).⁴⁹ The potassium channel–opening activity of minoxidil may induce stimulation of microcirculation around hair follicles conducive to hair growth.⁵⁰ Other proposed mechanisms for hair growth with minoxidil include effects on keratinocyte and fibroblast cell proliferation,^51-53 collagen synthesis,^52,54 and prostaglandin activity.^44,55

Final Thoughts

Medication-induced TE is an undesired adverse effect of many commonly used medications, including retinoids, azole antifungals, mood stabilizers, anticoagulants, and antihypertensives. In part 1⁵⁶ of this 2-part series, we reviewed the existing literature on hair loss from retinoids, antifungals, and psychotropic medications. Herein, we focused on anticoagulant and antihypertensive medications as potential culprits of TE. Heparin and its derivatives have been associated with development of diffuse alopecia weeks to months after the start of treatment. Alopecia associated with ACE inhibitors and β-blockers has been described only in case reports, suggesting that they may be unlikely causes of TE. In contrast, minoxidil is an antihypertensive that can result in hypertrichosis and is used in the treatment of androgenetic alopecia. It should not be assumed that medications that share an indication or are part of the same medication class would similarly induce TE. The development of diffuse nonscarring alopecia should prompt suspicion for TE and thorough investigation of medications initiated 1 to 6 months prior to onset of clinically apparent alopecia. Suspected culprit medications should be carefully assessed for their likelihood of inducing TE.

The Diagnosis: Cutaneous Rosai-Dorfman Disease

Rosai-Dorfman disease is a rare benign non- Langerhans cell histiocytopathy that can manifest initially with lymph node involvement—classically, massive painless cervical lymphadenopathy.¹ Cutaneous Rosai-Dorfman disease (CRDD) is a variant that can be associated with lymph node and internal involvement, but more than 80% of cases lack extracutaneous involvement.^2,3 In cases with extracutaneous involvement, lymph node disease is most frequent.3 Cutaneous Rosai-Dorfman disease unassociated with extracutaneous disease is a benign self-limiting histiocytopathy that manifests as painless red-brown, yellow, or fleshcolored nodules, plaques, or papules that may become tender or ulcerated.⁴

Cutaneous Rosai-Dorfman disease represents a benign histiocytopathy of resident dendritic cell derivation.³ A characteristic immunohistochemical finding is S-100 positivity, which might suggest a Langerhans cell transdifferentiation phenotype, but other markers corroborative of a Langerhans cell phenotype—namely CD1a and langerin—will be negative. Biopsies typically show a mid to deep dermal histiocytic infiltration in a variably dense polymorphous inflammatory cell background comprised of a mixture of lymphocytes, plasma cells, and neutrophils.³ At times the extent of lymphocytic infiltration can be to a magnitude that resembles a lymphoma on histopathology. In our patient, lymphoma was excluded based on clinical presentation, as this patient lacked the typical symptoms of lymphadenopathy or B symptoms that come with B-cell lymphoma.⁵

The histiocytes in CRDD are characteristically large mononuclear cells exhibiting a low nuclear to cytoplasmic ratio reflective of the voluminous, nonvacuolated, watery cytoplasm. They have ill-defined cytoplasmic membranes resulting in a seemingly syncytial growth pattern. A hallmark of the histiocytes is emperipolesis characterized by intracytoplasmic localization of intact inflammatory cells including neutrophils, lymphocytes, and plasma cells.³

The differential diagnosis of CRDD includes Langerhans cell histiocytosis (LCH), indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. All of these conditions can be differentiated by their unique histopathologic and phenotypic characteristics.

Langerhans cell histiocytosis is a distinct clonal histiocytopathy that has a varied presentation ranging from cutaneous confined cases manifesting as a solitary lesion to one of disseminated cutaneous disease with the potential for multiorgan involvement. Regardless of the variant of LCH, the hallmark cell is one showing an eccentrically disposed, reniform nucleus with an open chromatin and abundant eosinophilic cytoplasm (Figure 1).⁶ Both LCH and CRDD stain positive for S-100. However, unlike the histiocytes in CRDD, those seen in LCH stain positive for CD1a and langerin and would not express factor XIIIA. Additionally, the neoplastic cells would not exhibit the same extent of CD68 positivity seen in CRDD.⁶ Treatment of LCH depends on the extent of disease, especially for the presence or absence of extracutaneous disease.⁷

A variant of LCH is indeterminate cell histiocytosis, which can be seen in neonates or adults. It represents a neoplastic proliferation of Langerhans cells that are devoid of Birbeck granules, reflective of an immature early phase of differentiation in the skin prior to the cells acquiring the Birbeck granule (as would be seen in neonates) or a later phase of differentiation after the mature Langerhans cell has encountered antigen and is en route to the lymph node (typically seen in adults).⁸ The phenotypic profile is identical to conventional LCH except the cells do not express langerin. Microscopically, the infiltrates are composed of Langerhans cells that are morphologically indistinguishable from classic LCH but without epidermotropism and exhibit a dominant localization in the dermis typically unassociated with other inflammatory cell elements (Figure 2).⁹

Xanthogranuloma is seen in young children (juvenile xanthogranuloma) as a solitary lesion, though a multifocal cutaneous variant and extracutaneous presentations have been described. Similar lesions can be seen in adults.¹⁰ These lesions are evolutionary in their morphology. In the inception of a juvenile xanthogranuloma, the lesions are highly cellular, and the histiocytes typically are poorly lipidized; there may be a dearth of other inflammatory cell elements. As the lesions mature, the histiocytes become lipidized, and characteristic Touton giant cells that exhibit a wreath of nuclei with peripheral lipidization may develop (Figure 3). In the later stages, there is considerable hyalinizing fibrosis, and the cells can acquire a spindled appearance. The absence of emperipolesis and the presence of notable lipidization are useful light microscopy features differentiating xanthogranuloma from CRDD.¹¹ Treatment of xanthogranuloma can range from a conservative monitoring approach to an aggressive approach combining various antineoplastic therapies with immunosuppressive agents.¹²

Solitary and multicentric reticulohistiocytoma is another form of resident dendritic cell histiocytopathy that can resemble Rosai-Dorfman disease. It is a dermal histiocytic infiltrate accompanied by a polymorphous inflammatory cell infiltrate (Figure 4) and can show variable fibrosis.¹³ One of the hallmarks is the distinct amphophilic cytoplasms, possibly attributable to nuclear DNA released into the cytoplasm from effete nuclei.¹³ The solitary form is unassociated with systemic disease, whereas the multicentric variant can be a paraneoplastic syndrome in the setting of solid and hematologic malignancies.¹⁴ In addition, in the multicentric variant, similar lesions can affect any organ but there can be a proclivity to involve the hand and knee joints, leading to a crippling arthritis.¹⁵ We presented a case of CRDD, a benign resident dendritic cell histiocytopathy that can manifest as a cutaneous confined process in the skin where the clinical course is characteristically benign. It potentially can be confused with LCH, indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. For a solitary lesion, intralesional triamcinolone injection and excision are options. Multifocal cutaneous disease or CRDD with notable extracutaneous disease may require systemic treatment.16 In our patient, one intralesional triamcinolone injection was performed with notable resolution.

The Diagnosis: Cutaneous Rosai-Dorfman Disease

Rosai-Dorfman disease is a rare benign non- Langerhans cell histiocytopathy that can manifest initially with lymph node involvement—classically, massive painless cervical lymphadenopathy.¹ Cutaneous Rosai-Dorfman disease (CRDD) is a variant that can be associated with lymph node and internal involvement, but more than 80% of cases lack extracutaneous involvement.^2,3 In cases with extracutaneous involvement, lymph node disease is most frequent.3 Cutaneous Rosai-Dorfman disease unassociated with extracutaneous disease is a benign self-limiting histiocytopathy that manifests as painless red-brown, yellow, or fleshcolored nodules, plaques, or papules that may become tender or ulcerated.⁴

Cutaneous Rosai-Dorfman disease represents a benign histiocytopathy of resident dendritic cell derivation.³ A characteristic immunohistochemical finding is S-100 positivity, which might suggest a Langerhans cell transdifferentiation phenotype, but other markers corroborative of a Langerhans cell phenotype—namely CD1a and langerin—will be negative. Biopsies typically show a mid to deep dermal histiocytic infiltration in a variably dense polymorphous inflammatory cell background comprised of a mixture of lymphocytes, plasma cells, and neutrophils.³ At times the extent of lymphocytic infiltration can be to a magnitude that resembles a lymphoma on histopathology. In our patient, lymphoma was excluded based on clinical presentation, as this patient lacked the typical symptoms of lymphadenopathy or B symptoms that come with B-cell lymphoma.⁵

The histiocytes in CRDD are characteristically large mononuclear cells exhibiting a low nuclear to cytoplasmic ratio reflective of the voluminous, nonvacuolated, watery cytoplasm. They have ill-defined cytoplasmic membranes resulting in a seemingly syncytial growth pattern. A hallmark of the histiocytes is emperipolesis characterized by intracytoplasmic localization of intact inflammatory cells including neutrophils, lymphocytes, and plasma cells.³

The differential diagnosis of CRDD includes Langerhans cell histiocytosis (LCH), indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. All of these conditions can be differentiated by their unique histopathologic and phenotypic characteristics.

Langerhans cell histiocytosis is a distinct clonal histiocytopathy that has a varied presentation ranging from cutaneous confined cases manifesting as a solitary lesion to one of disseminated cutaneous disease with the potential for multiorgan involvement. Regardless of the variant of LCH, the hallmark cell is one showing an eccentrically disposed, reniform nucleus with an open chromatin and abundant eosinophilic cytoplasm (Figure 1).⁶ Both LCH and CRDD stain positive for S-100. However, unlike the histiocytes in CRDD, those seen in LCH stain positive for CD1a and langerin and would not express factor XIIIA. Additionally, the neoplastic cells would not exhibit the same extent of CD68 positivity seen in CRDD.⁶ Treatment of LCH depends on the extent of disease, especially for the presence or absence of extracutaneous disease.⁷

A variant of LCH is indeterminate cell histiocytosis, which can be seen in neonates or adults. It represents a neoplastic proliferation of Langerhans cells that are devoid of Birbeck granules, reflective of an immature early phase of differentiation in the skin prior to the cells acquiring the Birbeck granule (as would be seen in neonates) or a later phase of differentiation after the mature Langerhans cell has encountered antigen and is en route to the lymph node (typically seen in adults).⁸ The phenotypic profile is identical to conventional LCH except the cells do not express langerin. Microscopically, the infiltrates are composed of Langerhans cells that are morphologically indistinguishable from classic LCH but without epidermotropism and exhibit a dominant localization in the dermis typically unassociated with other inflammatory cell elements (Figure 2).⁹

Xanthogranuloma is seen in young children (juvenile xanthogranuloma) as a solitary lesion, though a multifocal cutaneous variant and extracutaneous presentations have been described. Similar lesions can be seen in adults.¹⁰ These lesions are evolutionary in their morphology. In the inception of a juvenile xanthogranuloma, the lesions are highly cellular, and the histiocytes typically are poorly lipidized; there may be a dearth of other inflammatory cell elements. As the lesions mature, the histiocytes become lipidized, and characteristic Touton giant cells that exhibit a wreath of nuclei with peripheral lipidization may develop (Figure 3). In the later stages, there is considerable hyalinizing fibrosis, and the cells can acquire a spindled appearance. The absence of emperipolesis and the presence of notable lipidization are useful light microscopy features differentiating xanthogranuloma from CRDD.¹¹ Treatment of xanthogranuloma can range from a conservative monitoring approach to an aggressive approach combining various antineoplastic therapies with immunosuppressive agents.¹²

Solitary and multicentric reticulohistiocytoma is another form of resident dendritic cell histiocytopathy that can resemble Rosai-Dorfman disease. It is a dermal histiocytic infiltrate accompanied by a polymorphous inflammatory cell infiltrate (Figure 4) and can show variable fibrosis.¹³ One of the hallmarks is the distinct amphophilic cytoplasms, possibly attributable to nuclear DNA released into the cytoplasm from effete nuclei.¹³ The solitary form is unassociated with systemic disease, whereas the multicentric variant can be a paraneoplastic syndrome in the setting of solid and hematologic malignancies.¹⁴ In addition, in the multicentric variant, similar lesions can affect any organ but there can be a proclivity to involve the hand and knee joints, leading to a crippling arthritis.¹⁵ We presented a case of CRDD, a benign resident dendritic cell histiocytopathy that can manifest as a cutaneous confined process in the skin where the clinical course is characteristically benign. It potentially can be confused with LCH, indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. For a solitary lesion, intralesional triamcinolone injection and excision are options. Multifocal cutaneous disease or CRDD with notable extracutaneous disease may require systemic treatment.16 In our patient, one intralesional triamcinolone injection was performed with notable resolution.

The Diagnosis: Cutaneous Rosai-Dorfman Disease

Rosai-Dorfman disease is a rare benign non- Langerhans cell histiocytopathy that can manifest initially with lymph node involvement—classically, massive painless cervical lymphadenopathy.¹ Cutaneous Rosai-Dorfman disease (CRDD) is a variant that can be associated with lymph node and internal involvement, but more than 80% of cases lack extracutaneous involvement.^2,3 In cases with extracutaneous involvement, lymph node disease is most frequent.3 Cutaneous Rosai-Dorfman disease unassociated with extracutaneous disease is a benign self-limiting histiocytopathy that manifests as painless red-brown, yellow, or fleshcolored nodules, plaques, or papules that may become tender or ulcerated.⁴

Cutaneous Rosai-Dorfman disease represents a benign histiocytopathy of resident dendritic cell derivation.³ A characteristic immunohistochemical finding is S-100 positivity, which might suggest a Langerhans cell transdifferentiation phenotype, but other markers corroborative of a Langerhans cell phenotype—namely CD1a and langerin—will be negative. Biopsies typically show a mid to deep dermal histiocytic infiltration in a variably dense polymorphous inflammatory cell background comprised of a mixture of lymphocytes, plasma cells, and neutrophils.³ At times the extent of lymphocytic infiltration can be to a magnitude that resembles a lymphoma on histopathology. In our patient, lymphoma was excluded based on clinical presentation, as this patient lacked the typical symptoms of lymphadenopathy or B symptoms that come with B-cell lymphoma.⁵

The histiocytes in CRDD are characteristically large mononuclear cells exhibiting a low nuclear to cytoplasmic ratio reflective of the voluminous, nonvacuolated, watery cytoplasm. They have ill-defined cytoplasmic membranes resulting in a seemingly syncytial growth pattern. A hallmark of the histiocytes is emperipolesis characterized by intracytoplasmic localization of intact inflammatory cells including neutrophils, lymphocytes, and plasma cells.³

The differential diagnosis of CRDD includes Langerhans cell histiocytosis (LCH), indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. All of these conditions can be differentiated by their unique histopathologic and phenotypic characteristics.

Langerhans cell histiocytosis is a distinct clonal histiocytopathy that has a varied presentation ranging from cutaneous confined cases manifesting as a solitary lesion to one of disseminated cutaneous disease with the potential for multiorgan involvement. Regardless of the variant of LCH, the hallmark cell is one showing an eccentrically disposed, reniform nucleus with an open chromatin and abundant eosinophilic cytoplasm (Figure 1).⁶ Both LCH and CRDD stain positive for S-100. However, unlike the histiocytes in CRDD, those seen in LCH stain positive for CD1a and langerin and would not express factor XIIIA. Additionally, the neoplastic cells would not exhibit the same extent of CD68 positivity seen in CRDD.⁶ Treatment of LCH depends on the extent of disease, especially for the presence or absence of extracutaneous disease.⁷

A variant of LCH is indeterminate cell histiocytosis, which can be seen in neonates or adults. It represents a neoplastic proliferation of Langerhans cells that are devoid of Birbeck granules, reflective of an immature early phase of differentiation in the skin prior to the cells acquiring the Birbeck granule (as would be seen in neonates) or a later phase of differentiation after the mature Langerhans cell has encountered antigen and is en route to the lymph node (typically seen in adults).⁸ The phenotypic profile is identical to conventional LCH except the cells do not express langerin. Microscopically, the infiltrates are composed of Langerhans cells that are morphologically indistinguishable from classic LCH but without epidermotropism and exhibit a dominant localization in the dermis typically unassociated with other inflammatory cell elements (Figure 2).⁹

Xanthogranuloma is seen in young children (juvenile xanthogranuloma) as a solitary lesion, though a multifocal cutaneous variant and extracutaneous presentations have been described. Similar lesions can be seen in adults.¹⁰ These lesions are evolutionary in their morphology. In the inception of a juvenile xanthogranuloma, the lesions are highly cellular, and the histiocytes typically are poorly lipidized; there may be a dearth of other inflammatory cell elements. As the lesions mature, the histiocytes become lipidized, and characteristic Touton giant cells that exhibit a wreath of nuclei with peripheral lipidization may develop (Figure 3). In the later stages, there is considerable hyalinizing fibrosis, and the cells can acquire a spindled appearance. The absence of emperipolesis and the presence of notable lipidization are useful light microscopy features differentiating xanthogranuloma from CRDD.¹¹ Treatment of xanthogranuloma can range from a conservative monitoring approach to an aggressive approach combining various antineoplastic therapies with immunosuppressive agents.¹²

Solitary and multicentric reticulohistiocytoma is another form of resident dendritic cell histiocytopathy that can resemble Rosai-Dorfman disease. It is a dermal histiocytic infiltrate accompanied by a polymorphous inflammatory cell infiltrate (Figure 4) and can show variable fibrosis.¹³ One of the hallmarks is the distinct amphophilic cytoplasms, possibly attributable to nuclear DNA released into the cytoplasm from effete nuclei.¹³ The solitary form is unassociated with systemic disease, whereas the multicentric variant can be a paraneoplastic syndrome in the setting of solid and hematologic malignancies.¹⁴ In addition, in the multicentric variant, similar lesions can affect any organ but there can be a proclivity to involve the hand and knee joints, leading to a crippling arthritis.¹⁵ We presented a case of CRDD, a benign resident dendritic cell histiocytopathy that can manifest as a cutaneous confined process in the skin where the clinical course is characteristically benign. It potentially can be confused with LCH, indeterminate cell histiocytosis, xanthogranuloma, and reticulohistiocytoma. For a solitary lesion, intralesional triamcinolone injection and excision are options. Multifocal cutaneous disease or CRDD with notable extracutaneous disease may require systemic treatment.16 In our patient, one intralesional triamcinolone injection was performed with notable resolution.

When it comes to selecting medical treatments for androgenetic alopecia (AGA), patients and practitioners alike want to know, “What works?” The ideal AGA treatment is one that meets 4 criteria: highly effective, safe, affordable, and easy to use. To date, there is no known treatment for AGA that meets all these criteria. Some therapies are more effective than others, but there are no treatments at present that are able to completely and permanently reverse the condition. Some treatments are safer, some are less expensive, and some are easier to use than others. In the end, the treatment that the patient chooses is influenced not only by its known effectiveness but also by the value that the patient places on the other 3 categories—safety, affordability, and ease of use. Therefore, shared decision-making between patient and practitioner is central to the selection of specific AGA treatments.

Effectiveness: Some Treatments Work Better Than Others

Of the nearly 2 dozen medical treatments for AGA, some have been found to be more effective than others. Whether a given treatment should be considered a bona fide AGA therapy—and then whether to position it as a first-line, second-line, or third-line agent—depends on the answers to 3 fundamental questions:

1. Does the treatment truly help patients with AGA?
2. How effective is this treatment?
3. How safe is it?

Does the Treatment Truly Help Patients?—Surprisingly, it is not always straightforward to confirm that a given treatment helps patients with AGA. Does oral finasteride help female AGA? Yes and no: Finasteride 1 mg is ineffective in the treatment of female AGA, but higher doses such as 2.5 or 5 mg likely have benefit.^1,2 Does topical minoxidil help AGA? Yes and no: Minoxidil 5% is ineffective in the treatment of a male with Hamilton-Norwood stage VII AGA but often is helpful in earlier stages of the condition.

One of the best ways to determine if a treatment really helps AGA is to evaluate how it performs in the setting of a well-conducted, randomized, double-blind, placebo-controlled trial. These types of clinical trials have been performed for many known AGA treatments and give us some of the best evidence that a treatment truly works. The AGA treatments with the highest-quality evidence (level 1) are topical minoxidil, oral finasteride, and oral dutasteride for male AGA and topical minoxidil for female AGA.

How Effective Is This Treatment?—Patients are particularly interested to know whether a given treatment has the potential to notably restore hair density. It is one thing to know that use of the treatment might slightly improve hair density and another to know that it could potentially lead to dramatic improvement. In addition, patients want to know whether a specific treatment they are considering is more (or less) likely to improve their hair density compared to another treatment.

Advanced statistical methods such as the network meta-analysis are increasingly being used to understand how individual treatments from different studies compare. Two recent studies have provided us with powerful data on the relative efficacy of minoxidil and 5α-reductase inhibitors in the treatment of both male and female AGA.^2,3 A 2022 network meta-analysis of male AGA ranked treatment efficacy from most to least effective: oral dutasteride 0.5 mg, oral finasteride 5 mg, oral minoxidil 5 mg, oral finasteride 1 mg, and topical minoxidil 5%.³ Similarly, a 2023 network meta-analysis of female AGA ranked treatment efficacy from most to least effective: oral 5 mg finasteride, minoxidil solution 5% twice daily, oral minoxidil 1 mg, and minoxidil foam 5% once daily.² We are not yet able to rank all known treatments for AGA.

Things We Tend to Ignore: Quality of Data, Long-term Results, Nonresponders, and Study Populations—There are a few caveats for anyone treating AGA. First, the quality of published AGA studies is highly variable and many are of low quality. The highest-quality evidence (level 1) for male AGA comes from studies of minoxidil solution/foam 5% twice daily, oral finasteride 1 mg, and oral dutasteride 0.5 mg. For female AGA, the highest-quality evidence is for topical minoxidil—either 5% foam once daily or 2% solution twice daily. Lower-quality studies limit conclusions and the ability to properly compare treatments.

Second, long-term data are nonexistent for most of our AGA treatments. The exceptions include finasteride, dutasteride, and topical minoxidil, which have reasonably adequate long-term studies.^4-6 However, most other treatments have been evaluated only through short-term studies. It is tempting to assume that results from a 24-week study can be used to infer how a patient might respond when using the same treatment over the course of many decades; however, making these assumptions would be unwise.

Third, most AGA treatments help improve hair density in only a proportion of patients who decide to use the given treatment. There usually is one subgroup of patients for whom the treatment does not seem to help much at all and one subgroup for whom the treatment halts further hair loss but does not regrow hair. For example, in the case of finasteride treatment of male AGA, approximately 10% of patients do not seem to respond to treatment at all, and another 50% seem to be able to halt further loss but never achieve hair regrowth.⁷ In an analysis of 12 studies with 3927 male patients, Mella et al⁸ showed that 5.6 patients needed to be treated short term and 3.4 patients needed to be treated long term for 1 patient to perceive an improvement in the hair. It is clear that many males who use finasteride will not see evidence of hair regrowth. This same general concept applies for all available treatments and is important to remember if a patient with AGA decides to start 2 new treatments simultaneously. Consider the 34-year-old man who starts oral minoxidil and platelet-rich plasma (PRP) for AGA. At his follow-up appointment 9 months later, the patient reports improved hair density and wants to know what contributed to the improvement: the oral minoxidil, the PRP, or both? Many practitioners would believe that both treatments likely provided some degree of benefit—but in reality, that represents a flaw in logic. If 2 hair loss treatments are started at exactly the same time, it is impossible to know the relative benefit of each treatment and whether one might not be helping at all. Combination therapies are still common in my practice and highly encouraged, but my personal preference is to stagger start dates whenever possible so I can determine each treatment’s contribution to the patient’s final outcome.

Finally, when evaluating what works for AGA, we need to define the specific patient subpopulation, as the available data are less robust for some patient groups than others. We have limited data in children and adolescents with AGA, as well as limited comparative data across different racial backgrounds, body mass indices, and underlying health issues. For example, data on the most effective strategies to treat female AGA in the setting of polycystic ovary syndrome, premature menopause, and other endocrine disorders are lacking.

Which Treatments Also Have Good Safety?—The treatment that a patient ultimately selects also depends on its actual or perceived safety. Patients have vastly different levels of risk tolerance. Some patients would much rather start a less effective treatment if they believe that the chances of experiencing treatment-related adverse effects would be lower. In general, topical and injectable treatments tend to have fewer adverse effects than oral therapies. Long-term safety data generally are lacking for many hair-loss therapies. A limited number of studies of topical minoxidil include data up to 5 years,⁴ and some studies of oral finasteride and oral dutasteride include patients who used these medications for up to 10 years.^5,6

So Then, What Works?

The Table shows treatments for AGA and how I prioritize starting them in my own clinic. First-line treatment options often include those with level 1 evidence but also may include those with less-robust evidence plus a good history (over many years) of safety, affordability, ease of use, and effectiveness (eg, spironolactone and finasteride for female-pattern hair loss).

• Male AGA: I consider topical minoxidil, oral finasteride, and oral dutasteride as first-line agents, and low-level laser, PRP, oral minoxidil, and topical finasteride as second-line agents. Only topical minoxidil and oral finasteride are approved by the US Food and Drug Administration (FDA) for AGA in males; laser devices are FDA cleared.

• Premenopausal females with AGA: I use topical minoxidil and spironolactone as first-line agents. Low-level laser, PRP, oral minoxidil, and oral contraceptives are helpful second-line agents. Only topical minoxidil is FDA approved in women. I consider all treatments, with the exception of low-level laser, to be contraindicated in pregnancy.

• Postmenopausal females with AGA: I consider topical minoxidil, spironolactone, and oral finasteride as first-line agents. Low-level laser, PRP, oral minoxidil, and oral dutasteride are helpful second-line agents.

When choosing an initial treatment plan, I generally will start with one or more first-line options. I will then add or replace with remaining first-line options or a second-line option after 6 to 12 months depending on how well the patient responds to the first-line options. Patients who do not wish to use first-line options or have contraindications begin with second-line options. Third-line options are best reserved for patients who do not respond to or do not wish to use first- and second-line options.

Experts differ in opinion as to what constitutes a first-line treatment option and what constitutes a second- or third-line option. For example, some increasingly consider oral minoxidil to be a first-line option for AGA.⁹ In my opinion, the lack of high-quality comparative, randomized, controlled trials and long-term safety data keep oral minoxidil reserved as a respectable second-line option. Similarly, some experts reserve oral dutasteride as a second-line option for AGA.¹⁰ In my opinion, the data now are of the highest-quality evidence (level 1)⁹ to support placing oral dutasteride in the tier of first-line treatments.

Shared decision-making using an evidence-based approach is ultimately what connects patients with treatment plans that offer a good chance of helping to improve hair loss.

When it comes to selecting medical treatments for androgenetic alopecia (AGA), patients and practitioners alike want to know, “What works?” The ideal AGA treatment is one that meets 4 criteria: highly effective, safe, affordable, and easy to use. To date, there is no known treatment for AGA that meets all these criteria. Some therapies are more effective than others, but there are no treatments at present that are able to completely and permanently reverse the condition. Some treatments are safer, some are less expensive, and some are easier to use than others. In the end, the treatment that the patient chooses is influenced not only by its known effectiveness but also by the value that the patient places on the other 3 categories—safety, affordability, and ease of use. Therefore, shared decision-making between patient and practitioner is central to the selection of specific AGA treatments.

Effectiveness: Some Treatments Work Better Than Others

Of the nearly 2 dozen medical treatments for AGA, some have been found to be more effective than others. Whether a given treatment should be considered a bona fide AGA therapy—and then whether to position it as a first-line, second-line, or third-line agent—depends on the answers to 3 fundamental questions:

1. Does the treatment truly help patients with AGA?
2. How effective is this treatment?
3. How safe is it?

Does the Treatment Truly Help Patients?—Surprisingly, it is not always straightforward to confirm that a given treatment helps patients with AGA. Does oral finasteride help female AGA? Yes and no: Finasteride 1 mg is ineffective in the treatment of female AGA, but higher doses such as 2.5 or 5 mg likely have benefit.^1,2 Does topical minoxidil help AGA? Yes and no: Minoxidil 5% is ineffective in the treatment of a male with Hamilton-Norwood stage VII AGA but often is helpful in earlier stages of the condition.

One of the best ways to determine if a treatment really helps AGA is to evaluate how it performs in the setting of a well-conducted, randomized, double-blind, placebo-controlled trial. These types of clinical trials have been performed for many known AGA treatments and give us some of the best evidence that a treatment truly works. The AGA treatments with the highest-quality evidence (level 1) are topical minoxidil, oral finasteride, and oral dutasteride for male AGA and topical minoxidil for female AGA.

How Effective Is This Treatment?—Patients are particularly interested to know whether a given treatment has the potential to notably restore hair density. It is one thing to know that use of the treatment might slightly improve hair density and another to know that it could potentially lead to dramatic improvement. In addition, patients want to know whether a specific treatment they are considering is more (or less) likely to improve their hair density compared to another treatment.

Advanced statistical methods such as the network meta-analysis are increasingly being used to understand how individual treatments from different studies compare. Two recent studies have provided us with powerful data on the relative efficacy of minoxidil and 5α-reductase inhibitors in the treatment of both male and female AGA.^2,3 A 2022 network meta-analysis of male AGA ranked treatment efficacy from most to least effective: oral dutasteride 0.5 mg, oral finasteride 5 mg, oral minoxidil 5 mg, oral finasteride 1 mg, and topical minoxidil 5%.³ Similarly, a 2023 network meta-analysis of female AGA ranked treatment efficacy from most to least effective: oral 5 mg finasteride, minoxidil solution 5% twice daily, oral minoxidil 1 mg, and minoxidil foam 5% once daily.² We are not yet able to rank all known treatments for AGA.

Things We Tend to Ignore: Quality of Data, Long-term Results, Nonresponders, and Study Populations—There are a few caveats for anyone treating AGA. First, the quality of published AGA studies is highly variable and many are of low quality. The highest-quality evidence (level 1) for male AGA comes from studies of minoxidil solution/foam 5% twice daily, oral finasteride 1 mg, and oral dutasteride 0.5 mg. For female AGA, the highest-quality evidence is for topical minoxidil—either 5% foam once daily or 2% solution twice daily. Lower-quality studies limit conclusions and the ability to properly compare treatments.

Second, long-term data are nonexistent for most of our AGA treatments. The exceptions include finasteride, dutasteride, and topical minoxidil, which have reasonably adequate long-term studies.^4-6 However, most other treatments have been evaluated only through short-term studies. It is tempting to assume that results from a 24-week study can be used to infer how a patient might respond when using the same treatment over the course of many decades; however, making these assumptions would be unwise.

Third, most AGA treatments help improve hair density in only a proportion of patients who decide to use the given treatment. There usually is one subgroup of patients for whom the treatment does not seem to help much at all and one subgroup for whom the treatment halts further hair loss but does not regrow hair. For example, in the case of finasteride treatment of male AGA, approximately 10% of patients do not seem to respond to treatment at all, and another 50% seem to be able to halt further loss but never achieve hair regrowth.⁷ In an analysis of 12 studies with 3927 male patients, Mella et al⁸ showed that 5.6 patients needed to be treated short term and 3.4 patients needed to be treated long term for 1 patient to perceive an improvement in the hair. It is clear that many males who use finasteride will not see evidence of hair regrowth. This same general concept applies for all available treatments and is important to remember if a patient with AGA decides to start 2 new treatments simultaneously. Consider the 34-year-old man who starts oral minoxidil and platelet-rich plasma (PRP) for AGA. At his follow-up appointment 9 months later, the patient reports improved hair density and wants to know what contributed to the improvement: the oral minoxidil, the PRP, or both? Many practitioners would believe that both treatments likely provided some degree of benefit—but in reality, that represents a flaw in logic. If 2 hair loss treatments are started at exactly the same time, it is impossible to know the relative benefit of each treatment and whether one might not be helping at all. Combination therapies are still common in my practice and highly encouraged, but my personal preference is to stagger start dates whenever possible so I can determine each treatment’s contribution to the patient’s final outcome.

Finally, when evaluating what works for AGA, we need to define the specific patient subpopulation, as the available data are less robust for some patient groups than others. We have limited data in children and adolescents with AGA, as well as limited comparative data across different racial backgrounds, body mass indices, and underlying health issues. For example, data on the most effective strategies to treat female AGA in the setting of polycystic ovary syndrome, premature menopause, and other endocrine disorders are lacking.

Which Treatments Also Have Good Safety?—The treatment that a patient ultimately selects also depends on its actual or perceived safety. Patients have vastly different levels of risk tolerance. Some patients would much rather start a less effective treatment if they believe that the chances of experiencing treatment-related adverse effects would be lower. In general, topical and injectable treatments tend to have fewer adverse effects than oral therapies. Long-term safety data generally are lacking for many hair-loss therapies. A limited number of studies of topical minoxidil include data up to 5 years,⁴ and some studies of oral finasteride and oral dutasteride include patients who used these medications for up to 10 years.^5,6

So Then, What Works?

The Table shows treatments for AGA and how I prioritize starting them in my own clinic. First-line treatment options often include those with level 1 evidence but also may include those with less-robust evidence plus a good history (over many years) of safety, affordability, ease of use, and effectiveness (eg, spironolactone and finasteride for female-pattern hair loss).

• Male AGA: I consider topical minoxidil, oral finasteride, and oral dutasteride as first-line agents, and low-level laser, PRP, oral minoxidil, and topical finasteride as second-line agents. Only topical minoxidil and oral finasteride are approved by the US Food and Drug Administration (FDA) for AGA in males; laser devices are FDA cleared.

• Premenopausal females with AGA: I use topical minoxidil and spironolactone as first-line agents. Low-level laser, PRP, oral minoxidil, and oral contraceptives are helpful second-line agents. Only topical minoxidil is FDA approved in women. I consider all treatments, with the exception of low-level laser, to be contraindicated in pregnancy.

• Postmenopausal females with AGA: I consider topical minoxidil, spironolactone, and oral finasteride as first-line agents. Low-level laser, PRP, oral minoxidil, and oral dutasteride are helpful second-line agents.

When choosing an initial treatment plan, I generally will start with one or more first-line options. I will then add or replace with remaining first-line options or a second-line option after 6 to 12 months depending on how well the patient responds to the first-line options. Patients who do not wish to use first-line options or have contraindications begin with second-line options. Third-line options are best reserved for patients who do not respond to or do not wish to use first- and second-line options.

Experts differ in opinion as to what constitutes a first-line treatment option and what constitutes a second- or third-line option. For example, some increasingly consider oral minoxidil to be a first-line option for AGA.⁹ In my opinion, the lack of high-quality comparative, randomized, controlled trials and long-term safety data keep oral minoxidil reserved as a respectable second-line option. Similarly, some experts reserve oral dutasteride as a second-line option for AGA.¹⁰ In my opinion, the data now are of the highest-quality evidence (level 1)⁹ to support placing oral dutasteride in the tier of first-line treatments.

Shared decision-making using an evidence-based approach is ultimately what connects patients with treatment plans that offer a good chance of helping to improve hair loss.

When it comes to selecting medical treatments for androgenetic alopecia (AGA), patients and practitioners alike want to know, “What works?” The ideal AGA treatment is one that meets 4 criteria: highly effective, safe, affordable, and easy to use. To date, there is no known treatment for AGA that meets all these criteria. Some therapies are more effective than others, but there are no treatments at present that are able to completely and permanently reverse the condition. Some treatments are safer, some are less expensive, and some are easier to use than others. In the end, the treatment that the patient chooses is influenced not only by its known effectiveness but also by the value that the patient places on the other 3 categories—safety, affordability, and ease of use. Therefore, shared decision-making between patient and practitioner is central to the selection of specific AGA treatments.

Effectiveness: Some Treatments Work Better Than Others

Of the nearly 2 dozen medical treatments for AGA, some have been found to be more effective than others. Whether a given treatment should be considered a bona fide AGA therapy—and then whether to position it as a first-line, second-line, or third-line agent—depends on the answers to 3 fundamental questions:

1. Does the treatment truly help patients with AGA?
2. How effective is this treatment?
3. How safe is it?

Does the Treatment Truly Help Patients?—Surprisingly, it is not always straightforward to confirm that a given treatment helps patients with AGA. Does oral finasteride help female AGA? Yes and no: Finasteride 1 mg is ineffective in the treatment of female AGA, but higher doses such as 2.5 or 5 mg likely have benefit.^1,2 Does topical minoxidil help AGA? Yes and no: Minoxidil 5% is ineffective in the treatment of a male with Hamilton-Norwood stage VII AGA but often is helpful in earlier stages of the condition.

One of the best ways to determine if a treatment really helps AGA is to evaluate how it performs in the setting of a well-conducted, randomized, double-blind, placebo-controlled trial. These types of clinical trials have been performed for many known AGA treatments and give us some of the best evidence that a treatment truly works. The AGA treatments with the highest-quality evidence (level 1) are topical minoxidil, oral finasteride, and oral dutasteride for male AGA and topical minoxidil for female AGA.

How Effective Is This Treatment?—Patients are particularly interested to know whether a given treatment has the potential to notably restore hair density. It is one thing to know that use of the treatment might slightly improve hair density and another to know that it could potentially lead to dramatic improvement. In addition, patients want to know whether a specific treatment they are considering is more (or less) likely to improve their hair density compared to another treatment.

Advanced statistical methods such as the network meta-analysis are increasingly being used to understand how individual treatments from different studies compare. Two recent studies have provided us with powerful data on the relative efficacy of minoxidil and 5α-reductase inhibitors in the treatment of both male and female AGA.^2,3 A 2022 network meta-analysis of male AGA ranked treatment efficacy from most to least effective: oral dutasteride 0.5 mg, oral finasteride 5 mg, oral minoxidil 5 mg, oral finasteride 1 mg, and topical minoxidil 5%.³ Similarly, a 2023 network meta-analysis of female AGA ranked treatment efficacy from most to least effective: oral 5 mg finasteride, minoxidil solution 5% twice daily, oral minoxidil 1 mg, and minoxidil foam 5% once daily.² We are not yet able to rank all known treatments for AGA.

Things We Tend to Ignore: Quality of Data, Long-term Results, Nonresponders, and Study Populations—There are a few caveats for anyone treating AGA. First, the quality of published AGA studies is highly variable and many are of low quality. The highest-quality evidence (level 1) for male AGA comes from studies of minoxidil solution/foam 5% twice daily, oral finasteride 1 mg, and oral dutasteride 0.5 mg. For female AGA, the highest-quality evidence is for topical minoxidil—either 5% foam once daily or 2% solution twice daily. Lower-quality studies limit conclusions and the ability to properly compare treatments.

Second, long-term data are nonexistent for most of our AGA treatments. The exceptions include finasteride, dutasteride, and topical minoxidil, which have reasonably adequate long-term studies.^4-6 However, most other treatments have been evaluated only through short-term studies. It is tempting to assume that results from a 24-week study can be used to infer how a patient might respond when using the same treatment over the course of many decades; however, making these assumptions would be unwise.

Third, most AGA treatments help improve hair density in only a proportion of patients who decide to use the given treatment. There usually is one subgroup of patients for whom the treatment does not seem to help much at all and one subgroup for whom the treatment halts further hair loss but does not regrow hair. For example, in the case of finasteride treatment of male AGA, approximately 10% of patients do not seem to respond to treatment at all, and another 50% seem to be able to halt further loss but never achieve hair regrowth.⁷ In an analysis of 12 studies with 3927 male patients, Mella et al⁸ showed that 5.6 patients needed to be treated short term and 3.4 patients needed to be treated long term for 1 patient to perceive an improvement in the hair. It is clear that many males who use finasteride will not see evidence of hair regrowth. This same general concept applies for all available treatments and is important to remember if a patient with AGA decides to start 2 new treatments simultaneously. Consider the 34-year-old man who starts oral minoxidil and platelet-rich plasma (PRP) for AGA. At his follow-up appointment 9 months later, the patient reports improved hair density and wants to know what contributed to the improvement: the oral minoxidil, the PRP, or both? Many practitioners would believe that both treatments likely provided some degree of benefit—but in reality, that represents a flaw in logic. If 2 hair loss treatments are started at exactly the same time, it is impossible to know the relative benefit of each treatment and whether one might not be helping at all. Combination therapies are still common in my practice and highly encouraged, but my personal preference is to stagger start dates whenever possible so I can determine each treatment’s contribution to the patient’s final outcome.

Finally, when evaluating what works for AGA, we need to define the specific patient subpopulation, as the available data are less robust for some patient groups than others. We have limited data in children and adolescents with AGA, as well as limited comparative data across different racial backgrounds, body mass indices, and underlying health issues. For example, data on the most effective strategies to treat female AGA in the setting of polycystic ovary syndrome, premature menopause, and other endocrine disorders are lacking.

Which Treatments Also Have Good Safety?—The treatment that a patient ultimately selects also depends on its actual or perceived safety. Patients have vastly different levels of risk tolerance. Some patients would much rather start a less effective treatment if they believe that the chances of experiencing treatment-related adverse effects would be lower. In general, topical and injectable treatments tend to have fewer adverse effects than oral therapies. Long-term safety data generally are lacking for many hair-loss therapies. A limited number of studies of topical minoxidil include data up to 5 years,⁴ and some studies of oral finasteride and oral dutasteride include patients who used these medications for up to 10 years.^5,6

So Then, What Works?

The Table shows treatments for AGA and how I prioritize starting them in my own clinic. First-line treatment options often include those with level 1 evidence but also may include those with less-robust evidence plus a good history (over many years) of safety, affordability, ease of use, and effectiveness (eg, spironolactone and finasteride for female-pattern hair loss).

• Male AGA: I consider topical minoxidil, oral finasteride, and oral dutasteride as first-line agents, and low-level laser, PRP, oral minoxidil, and topical finasteride as second-line agents. Only topical minoxidil and oral finasteride are approved by the US Food and Drug Administration (FDA) for AGA in males; laser devices are FDA cleared.

• Premenopausal females with AGA: I use topical minoxidil and spironolactone as first-line agents. Low-level laser, PRP, oral minoxidil, and oral contraceptives are helpful second-line agents. Only topical minoxidil is FDA approved in women. I consider all treatments, with the exception of low-level laser, to be contraindicated in pregnancy.

• Postmenopausal females with AGA: I consider topical minoxidil, spironolactone, and oral finasteride as first-line agents. Low-level laser, PRP, oral minoxidil, and oral dutasteride are helpful second-line agents.

When choosing an initial treatment plan, I generally will start with one or more first-line options. I will then add or replace with remaining first-line options or a second-line option after 6 to 12 months depending on how well the patient responds to the first-line options. Patients who do not wish to use first-line options or have contraindications begin with second-line options. Third-line options are best reserved for patients who do not respond to or do not wish to use first- and second-line options.

Experts differ in opinion as to what constitutes a first-line treatment option and what constitutes a second- or third-line option. For example, some increasingly consider oral minoxidil to be a first-line option for AGA.⁹ In my opinion, the lack of high-quality comparative, randomized, controlled trials and long-term safety data keep oral minoxidil reserved as a respectable second-line option. Similarly, some experts reserve oral dutasteride as a second-line option for AGA.¹⁰ In my opinion, the data now are of the highest-quality evidence (level 1)⁹ to support placing oral dutasteride in the tier of first-line treatments.

Shared decision-making using an evidence-based approach is ultimately what connects patients with treatment plans that offer a good chance of helping to improve hair loss.