Abstract

Verrucous psoriasis is a rare variant of psoriasis characterized by hypertrophic plaques showing histologic features of psoriasis in addition to features reminiscent of verruca vulgaris. Verrucous changes associated with pustular psoriasis have not been previously described. Here, we report a 60-year-old female who was referred to the dermatology clinic with a 3-month history of expanding, tender, lesions on the lower extremities that were clinically concerning for malignancy. Her only relevant medical history was of vulvar squamous cell carcinoma, treated with surgery, radiation and chemotherapy 2.5-years prior to presentation. On exam, there was a 6 x 5 cm exophytic mass on the leg with a mamillated surface and purulent crust, and two smaller scaly plaques on the thigh and groin. Excisional biopsies were performed, and histopathology from all three lesions revealed a pustular psoriasiform dermatitis with classic features of psoriasis and presence of prominent intra-and subcorneal neutrophilic pustules. The exophytic lesion showed superimposed verrucous features of marked hyperkeratosis and papillomatosis. Eight months later, the patient presented in follow-up with two erythematous, pustular plaques on the foot that were clinically consistent with pustular psoriasis. These lesions were successfully treated with topical therapy. This case highlights a unique verrucous variant of pustular psoriasis that can present as a mass lesion and clinically mimic malignancy. In this case, the patient’s lesions appeared de novo without a known history of psoriasis or any obvious trigger. Recognition of verrucous forms of psoriasis is important as medical treatment is typically effective.

Financial Disclosure:
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