Large circular thigh rash

This patient had the deep form of erythema annulare centrifugum (EAC). As the name implies, it manifests as an expanding, red circular pattern that often clears in the middle. There is usually a ring of scale that trails behind the advancing border. However, in the deep form, it may be more subtle than the pronounced scale of the superficial form. Pruritus is a very common symptom associated with this condition.

EAC is a hypersensitivity reaction, which can be in response to several stimuli including underlying malignancy, medications, fungal and dermatophyte infections, inflammatory conditions, and pregnancy. A careful history and physical exam can be helpful in determining if a work-up for malignancy is warranted.

Since many medications including nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, and biologicals can cause this condition, a history of which medications were started within the previous several months may be helpful.

When EAC is due to an underlying malignancy, it is called paraneoplastic erythema annulare centrifugum. It can be secondary to solid tumors or lymphoproliferative disorders.

More than 50% percent of the cases are idiopathic, and no underlying condition is identified. The skin findings may last for weeks—and even years.

If an underlying cause is found, treatment is directed at that condition, and the skin findings usually improve with resolution of the instigating condition. If no specific cause is found, the itching can be managed with systemic antihistamines or topical steroids. Some case studies have reported success with the use of systemic antibiotics, including erythromycin. Improvement with antibiotics may be due to treatment of an occult underlying bacterial process or owing to the anti-inflammatory effects of many antibiotics.

Since the patient in this case had onychomycosis of his toenails, and fungal and dermatophyte infections are a common trigger, he was placed on a 12-week course of oral terbinafine 250 mg/d. The plan was to biopsy the rash if it didn’t resolve. At 3 weeks, the rash had resolved, and the patient was asymptomatic.

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Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.

This patient had the deep form of erythema annulare centrifugum (EAC). As the name implies, it manifests as an expanding, red circular pattern that often clears in the middle. There is usually a ring of scale that trails behind the advancing border. However, in the deep form, it may be more subtle than the pronounced scale of the superficial form. Pruritus is a very common symptom associated with this condition.

EAC is a hypersensitivity reaction, which can be in response to several stimuli including underlying malignancy, medications, fungal and dermatophyte infections, inflammatory conditions, and pregnancy. A careful history and physical exam can be helpful in determining if a work-up for malignancy is warranted.

Since many medications including nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, and biologicals can cause this condition, a history of which medications were started within the previous several months may be helpful.

When EAC is due to an underlying malignancy, it is called paraneoplastic erythema annulare centrifugum. It can be secondary to solid tumors or lymphoproliferative disorders.

More than 50% percent of the cases are idiopathic, and no underlying condition is identified. The skin findings may last for weeks—and even years.

If an underlying cause is found, treatment is directed at that condition, and the skin findings usually improve with resolution of the instigating condition. If no specific cause is found, the itching can be managed with systemic antihistamines or topical steroids. Some case studies have reported success with the use of systemic antibiotics, including erythromycin. Improvement with antibiotics may be due to treatment of an occult underlying bacterial process or owing to the anti-inflammatory effects of many antibiotics.

Since the patient in this case had onychomycosis of his toenails, and fungal and dermatophyte infections are a common trigger, he was placed on a 12-week course of oral terbinafine 250 mg/d. The plan was to biopsy the rash if it didn’t resolve. At 3 weeks, the rash had resolved, and the patient was asymptomatic.

‌

Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.

This patient had the deep form of erythema annulare centrifugum (EAC). As the name implies, it manifests as an expanding, red circular pattern that often clears in the middle. There is usually a ring of scale that trails behind the advancing border. However, in the deep form, it may be more subtle than the pronounced scale of the superficial form. Pruritus is a very common symptom associated with this condition.

EAC is a hypersensitivity reaction, which can be in response to several stimuli including underlying malignancy, medications, fungal and dermatophyte infections, inflammatory conditions, and pregnancy. A careful history and physical exam can be helpful in determining if a work-up for malignancy is warranted.

Since many medications including nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, and biologicals can cause this condition, a history of which medications were started within the previous several months may be helpful.

When EAC is due to an underlying malignancy, it is called paraneoplastic erythema annulare centrifugum. It can be secondary to solid tumors or lymphoproliferative disorders.

More than 50% percent of the cases are idiopathic, and no underlying condition is identified. The skin findings may last for weeks—and even years.

If an underlying cause is found, treatment is directed at that condition, and the skin findings usually improve with resolution of the instigating condition. If no specific cause is found, the itching can be managed with systemic antihistamines or topical steroids. Some case studies have reported success with the use of systemic antibiotics, including erythromycin. Improvement with antibiotics may be due to treatment of an occult underlying bacterial process or owing to the anti-inflammatory effects of many antibiotics.

Since the patient in this case had onychomycosis of his toenails, and fungal and dermatophyte infections are a common trigger, he was placed on a 12-week course of oral terbinafine 250 mg/d. The plan was to biopsy the rash if it didn’t resolve. At 3 weeks, the rash had resolved, and the patient was asymptomatic.

‌

Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.