Description: Peripheral white hoop of keratinization and a wrinkle-like appearance of the inner part

History:

Stucco keratosis was first described by Kocsard and Ofner in 1965 and later by Willoughby and Soter in 1972.

Stucco keratosis is a keratotic papule that is usually found on the distal lower acral extremities of males. It seems to appear with a higher frequency in males; however, it is not inherited genetically.

A 72-year-old-man presented multiple small, pale, round in shape, sharply demarcated keratotic papula and plaques on the lower extremities which had appeared 5 years before, they were surrounded by a thin hyperkeratotic border and were asymptomatic. The patient had a slight immunodepression, a sign commonly described in cases of stucco keratosis.

   In order to set a correct diagnosis the lesion was examined under dermoscope with following bunch biopsy. The dermoscopy of typical papula and plaques revealed a peripheral white hoop of keratinization and a wrinkle-like appearance of the inner part (more or less expressed) with accidental foci of central keratinization. The last criteria is often absent and is more commonly seen in larger plaques. The background is light-brown to brown in colour.

   A punch biopsy, performed in correspondence to the hyperkeratotic border of one lesion, revealed no dysplastic changes and a characteristic regular “church spire” type retention hyperkeratosis without marked acanthosis. In general, the histopathology resembled the appearance of the hyperkeratotic type of seborrheic keratosis with the absence of horn cysts and basaloid cells.

   The patient was treated with Lac-Hydrin (12% ammonium lactate) in alternation with 5% salicylic acid with fine results.