Pityriasis versicolor, also known as tinea versicolor, is a common fungal disease that can have several different appearances. These different appearances can be misleading for diagnosis and treatment. Also, pityriasis versicolor can be recurrent and persistent, leading to frustration for patients and providers.
Pityriasis versicolor is caused by the yeast Malassezia furfur. It is more common in areas of higher heat and humidity, but is found worldwide. In practice, it is often seen in younger patients who are involved in athletics, or in patients who have frequent contact with animals.
Classic pityriasis versicolor will be hypopigmented, slightly scaly, with random patches on the upper back, chest, and shoulders. However, it can also be salmon-colored or darkly colored. The patches can also appear on arms or legs, and on the face. Generally, there will be no other symptoms, although it can occasionally be pruritic. Patients often have the areas for months or years.
Diagnosing pityriasis versicolor is typically done based on the appearance of the rash. For confirmation, a Wood’s lamp will show yellow or green fluorescence. Pityriasis versicolor will usually be random, mildly dry/scaly, rough circular patches on the upper trunk, gradually worsening over time, but without other symptoms.
Given the different presentations of pityriasis versicolor, the differential can be broad, and includes eczema, pityriasis rosea, and even acanthosis nigricans if the patches bear darker coloration. These diagnoses can be ruled out based on symptoms and patterns: eczema will always be pruritic and usually follows a symmetrical pattern, pityriasis rosea usually follows a “Christmas tree” pattern and often has a herald patch, acanthosis nigricans will be limited to the neck and have a “velvet” appearance. A Wood’s lamp can also aid in diagnosis.
Selenium sulfide shampoo or ketoconazole shampoo OTC, clotrimazole, ciclopirox, and nystatin are typically used as initial treatments. Though these can be effective, unfortunately many patients only achieve a partial response or relapse. This can be due to a number of factors such as re-infection, lack of compliance, inability to apply to all areas, or improper use.
The most effective treatment is a combination of ketoconazole 2% cream twice daily to the affected area for four weeks, combined with oral fluconazole 150 mg or 300 mg once per week for four weeks. Itraconazole 200 mg per day for one week can also be used. This treatment seems to get the greatest clearance for the longest period of time.
Preventing re-infection with pityriasis versicolor is almost as important as treating the initial presentation. OTC selenium sulfide shampoo can be used once per week or more often if needed. Also, ketoconazole 2% cream can continue to be used as needed after clearance of the first infection.
Written by Charles Glass, PA