A Case of Dermatitis Neglecta.

Dermatitis neglecta (unwashed dermatosis) presents as pigmented hyperkeratotic plaques with adherent scales which clinically resembles psoriasis. This condition is the result of avoiding washing the affected areas, so the lesions are characteristically resolved with normal washing or with gentle wiping from an alcohol swab. We report a 29-year-old man who presented with an asymptomatic hyperkeratotic scaly plaque on umbilicus. A skin biopsy was done under the clinical impression of psoriasis. During skin biopsy, gentle swabbing with H2O2 and saline gauze was done. The patient revisited our clinic 10 days after the skin biopsy and the hyperkeratotic lesion had cleared. Histologic examination showed orthokeratotic hyperkeratosis and anastomosing rete ridges. There has been no previous report of dermatitis neglecta with histologic confirmation, and so this case could be the first report to provide the histologic characteristics of dermatitis neglecta. Because this condition might be overlooked and underdiagnosed, recognizing its existence and cause are important to avoid unnecessary biopsies and potentially aggressive therapeutic measures.