In September of 1958, a 38-year-old woman of Latin American extraction appeared in my office for the treatment of a skin eruption involving the face and forehead. Examination revealed large, sharply circumscribed areas of mild hyperpigmentation on both cheeks, on both sides of the chin, and on the forehead. Within these areas were located hundreds of flat warts. The forehead was almost a solid mosaic of warts (Figure).
The patient gave the following history. Three months previously she had been treated elsewhere for four flat warts, which were located on the left lower cheek. These lesions had been cauterized with a dilute solution of trichloroacetic acid. Scars followed this therapy. Subsequently, a full face wire brush planing was performed. This procedure was followed by the appearance of myriads of flat warts within the abraded areas.
Attempts at removal of these lesions during succeeding months by various destructive methods were unsuccessful.