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NEW YORK – Clinical information evolves even for one of the most common dermatologic diseases, Malassezia infections; namely, progress in characterizing the species and the impact of a recent labeling change for oral ketoconazole, according to Dr. Nikki A. Levin of the University of Massachusetts, Worcester.
In a statement issued in July, "the [Food and Drug Administration] has limited the use or oral ketoconazole for invasive fungal infections because of concern about cases of fatal hepatotoxicity," Dr. Levin said.
Dr. Levin acknowledged ketoconazole as her go-to drug for tinea versicolor in patients not willing to use topical therapies, but she added that the new restrictions have changed her practice. She considers once-weekly fluconazole and itraconazole the best alternatives, noting only that the latter agent poses a higher risk of interactions in patients taking other drugs.
The relative efficacy of the FDA-approved options for topical therapy, including ketoconazole, econazole, clotrimazole, and miconazole, are difficult to judge because comparative studies are limited, Dr. Levin said. But the efficacy should be high for patients who apply any of these treatments twice a day for at least 3 weeks, she added.
A long list of agents not yet approved by the FDA have shown efficacy against tinea versicolor, but over-the-counter selenium sulfide lotion for skin infections or shampoo for scalp infections also are generally effective, Dr. Levin said.
Empirical use of these therapies is reasonable when patients show classic clinical signs of infection, said Dr. Levin. Malassezia prefers lipid-rich environments, and so it is most often found where sebaceous glands cluster, such as the face, scalp, and upper trunk. The creation of scales when a skin lesion is scraped (evoked scale sign), is generally sufficient to confirm the diagnosis when the KOH, or potassium hydroxide, test is positive, and cultures are rarely needed and can be problematic, Dr. Levin said. In fact, she cautioned that lipids are needed in the medium for the yeast to grow, so specimens sent to a lab should be accompanied by a specific request to demonstrate this infection.
In a presentation at the American Academy of Dermatology summer meeting, Dr. Levin also discussed evolving concepts that better characterize these yeast infections, including their appearance on light microscopy.
"In medical school, you are taught to recognize the spaghetti and meatball appearance of the short hyphae and the little spores, but since when are meatballs smaller than spaghetti? I am proposing that we change this to pasta primavera," said Dr. Levin, who likened the appearance of M. globus, which is one of the most common causes of tinea versicolor, to penne with peas.
The knowledge base on Malassezia overall and on species relevant to human infection in particular continues to grow, said Dr. Levin. She reported that the M. globosa genome was recently sequenced, and biochemistry studies have yielded new insights into how these organisms defeat immune defenses and alter melanin production to change skin pigmentation. However, she acknowledged that the immediate clinical relevance of this information is limited without further research.
The characterization of Malassezia continues to evolve, with an expansion of species to 14 from the previous 7, but differentiating among the species is not typically necessary in evaluating human infections, Dr. Levin said.
Malassezia infections, most commonly encountered as tinea versicolor, are extremely common, generally responsive to topical and oral therapies, and reasonably diagnosed in most cases on the basis of its classical clinical appearance without biopsy or culture.
"You may ask yourself, do I care about the taxonomy?" asked Dr. Levin. And the answer might be perhaps not. "In general, the treatment for these infections is the same," she said.
Dr. Levin disclosed a financial relationship with Amgen, but reported no disclosures relevant to her presentation.
NEW YORK – Clinical information evolves even for one of the most common dermatologic diseases, Malassezia infections; namely, progress in characterizing the species and the impact of a recent labeling change for oral ketoconazole, according to Dr. Nikki A. Levin of the University of Massachusetts, Worcester.
In a statement issued in July, "the [Food and Drug Administration] has limited the use or oral ketoconazole for invasive fungal infections because of concern about cases of fatal hepatotoxicity," Dr. Levin said.
Dr. Levin acknowledged ketoconazole as her go-to drug for tinea versicolor in patients not willing to use topical therapies, but she added that the new restrictions have changed her practice. She considers once-weekly fluconazole and itraconazole the best alternatives, noting only that the latter agent poses a higher risk of interactions in patients taking other drugs.
The relative efficacy of the FDA-approved options for topical therapy, including ketoconazole, econazole, clotrimazole, and miconazole, are difficult to judge because comparative studies are limited, Dr. Levin said. But the efficacy should be high for patients who apply any of these treatments twice a day for at least 3 weeks, she added.
A long list of agents not yet approved by the FDA have shown efficacy against tinea versicolor, but over-the-counter selenium sulfide lotion for skin infections or shampoo for scalp infections also are generally effective, Dr. Levin said.
Empirical use of these therapies is reasonable when patients show classic clinical signs of infection, said Dr. Levin. Malassezia prefers lipid-rich environments, and so it is most often found where sebaceous glands cluster, such as the face, scalp, and upper trunk. The creation of scales when a skin lesion is scraped (evoked scale sign), is generally sufficient to confirm the diagnosis when the KOH, or potassium hydroxide, test is positive, and cultures are rarely needed and can be problematic, Dr. Levin said. In fact, she cautioned that lipids are needed in the medium for the yeast to grow, so specimens sent to a lab should be accompanied by a specific request to demonstrate this infection.
In a presentation at the American Academy of Dermatology summer meeting, Dr. Levin also discussed evolving concepts that better characterize these yeast infections, including their appearance on light microscopy.
"In medical school, you are taught to recognize the spaghetti and meatball appearance of the short hyphae and the little spores, but since when are meatballs smaller than spaghetti? I am proposing that we change this to pasta primavera," said Dr. Levin, who likened the appearance of M. globus, which is one of the most common causes of tinea versicolor, to penne with peas.
The knowledge base on Malassezia overall and on species relevant to human infection in particular continues to grow, said Dr. Levin. She reported that the M. globosa genome was recently sequenced, and biochemistry studies have yielded new insights into how these organisms defeat immune defenses and alter melanin production to change skin pigmentation. However, she acknowledged that the immediate clinical relevance of this information is limited without further research.
The characterization of Malassezia continues to evolve, with an expansion of species to 14 from the previous 7, but differentiating among the species is not typically necessary in evaluating human infections, Dr. Levin said.
Malassezia infections, most commonly encountered as tinea versicolor, are extremely common, generally responsive to topical and oral therapies, and reasonably diagnosed in most cases on the basis of its classical clinical appearance without biopsy or culture.
"You may ask yourself, do I care about the taxonomy?" asked Dr. Levin. And the answer might be perhaps not. "In general, the treatment for these infections is the same," she said.
Dr. Levin disclosed a financial relationship with Amgen, but reported no disclosures relevant to her presentation.
NEW YORK – Clinical information evolves even for one of the most common dermatologic diseases, Malassezia infections; namely, progress in characterizing the species and the impact of a recent labeling change for oral ketoconazole, according to Dr. Nikki A. Levin of the University of Massachusetts, Worcester.
In a statement issued in July, "the [Food and Drug Administration] has limited the use or oral ketoconazole for invasive fungal infections because of concern about cases of fatal hepatotoxicity," Dr. Levin said.
Dr. Levin acknowledged ketoconazole as her go-to drug for tinea versicolor in patients not willing to use topical therapies, but she added that the new restrictions have changed her practice. She considers once-weekly fluconazole and itraconazole the best alternatives, noting only that the latter agent poses a higher risk of interactions in patients taking other drugs.
The relative efficacy of the FDA-approved options for topical therapy, including ketoconazole, econazole, clotrimazole, and miconazole, are difficult to judge because comparative studies are limited, Dr. Levin said. But the efficacy should be high for patients who apply any of these treatments twice a day for at least 3 weeks, she added.
A long list of agents not yet approved by the FDA have shown efficacy against tinea versicolor, but over-the-counter selenium sulfide lotion for skin infections or shampoo for scalp infections also are generally effective, Dr. Levin said.
Empirical use of these therapies is reasonable when patients show classic clinical signs of infection, said Dr. Levin. Malassezia prefers lipid-rich environments, and so it is most often found where sebaceous glands cluster, such as the face, scalp, and upper trunk. The creation of scales when a skin lesion is scraped (evoked scale sign), is generally sufficient to confirm the diagnosis when the KOH, or potassium hydroxide, test is positive, and cultures are rarely needed and can be problematic, Dr. Levin said. In fact, she cautioned that lipids are needed in the medium for the yeast to grow, so specimens sent to a lab should be accompanied by a specific request to demonstrate this infection.
In a presentation at the American Academy of Dermatology summer meeting, Dr. Levin also discussed evolving concepts that better characterize these yeast infections, including their appearance on light microscopy.
"In medical school, you are taught to recognize the spaghetti and meatball appearance of the short hyphae and the little spores, but since when are meatballs smaller than spaghetti? I am proposing that we change this to pasta primavera," said Dr. Levin, who likened the appearance of M. globus, which is one of the most common causes of tinea versicolor, to penne with peas.
The knowledge base on Malassezia overall and on species relevant to human infection in particular continues to grow, said Dr. Levin. She reported that the M. globosa genome was recently sequenced, and biochemistry studies have yielded new insights into how these organisms defeat immune defenses and alter melanin production to change skin pigmentation. However, she acknowledged that the immediate clinical relevance of this information is limited without further research.
The characterization of Malassezia continues to evolve, with an expansion of species to 14 from the previous 7, but differentiating among the species is not typically necessary in evaluating human infections, Dr. Levin said.
Malassezia infections, most commonly encountered as tinea versicolor, are extremely common, generally responsive to topical and oral therapies, and reasonably diagnosed in most cases on the basis of its classical clinical appearance without biopsy or culture.
"You may ask yourself, do I care about the taxonomy?" asked Dr. Levin. And the answer might be perhaps not. "In general, the treatment for these infections is the same," she said.
Dr. Levin disclosed a financial relationship with Amgen, but reported no disclosures relevant to her presentation.
EXPERT ANALYSIS FROM THE AAD SUMMER ACADEMY 2013