Pseudozoster clinical presentation of Demodex infestation after prolonged topical steroid use

Abstract

A 60-year-old man presented with a plaque lesion on the upper right half of the face, which had developed after ophthalmic varicella zoster infection about 2 years previously. The lesion, which was burning and itchy, included a few tiny erythematous pustules, and was slightly squamous and infiltrated. The lesion covered the upper two-thirds of the right trigeminal nerve dermatome, involving half of the face with the forehead, the periorbital area, upper part of the cheek and the nose. The lesion became more marked after continuous topical anaesthetic and corticosteroid use. A standardized skin-surface biopsy was taken, and revealed a large number of Demodex folliculorum (38/cm(2)) in the lesion area. The lesions completely abated after topical 5% permethrin treatment, and no recurrence was observed during follow-up. Demodicosis may have atypical clinical presentations, other than the well-known classic forms. To our knowledge, this is the first unilateral trigeminal, pseudozoster presentation in the literature.