[Linear ulcers with central keratinous plug].

Reactive perforating dermatosis (RPD) is a primary perforating dermatosis. Histologically, it presents with transepidermal discharge of basophile material and vertical arrangement of collagen fibers. RPD is treated using external keratolytic agents, topical and systemic glucocorticosteroids, retinoids and antihistamines. Good results have also been reported using photo(chemo)therapy. In the case study presented here, the patient responded very well to treatment with allopurinol.