Symptoms and Causes
This is a fairly new condition first described in the last 20-30 years. It presents with chronic moist, crusting, or oozing erosions over the top of the scalp. The lesions usually develop in areas that have been sun damaged (with actinic keratosis or skin cancer) followed by treatment such as Mohs surgery, use of skin cancer creams like 5-fluorouracil or imiquimod cream, or in the context of other systemic cancer fighting treatments such as capecitabine or bevacizumab. Interestingly, it has also been reported in the context of a glued-on hairpiece, as a result of contact allergy from the hair dye.
Diagnosis & Treatments
A scalp biopsy is helpful to confirm the diagnosis. It generally reveals a mixture of lymphocytes, plasma cells, and neutrophils. It can often appear to be an infection, with the classic ‘pus’ appearing present. However cultures of the area are usually negative. Occasionally gram-negative bacteria may be present, flourishing in moist lesions, but occurring as a secondary contaminant and not a primary pathogen.
High potency topical steroids clobetasol and betamethasone are generally effective in controlling the disorder and drying out the lesions. However the resultant alopecia may or may not be reversed.