Pustular psoriasis over keloids: is it a Koebner phenomenon?

Abstract

Conflict of interest: there is no conflict of interest. A 44‐year‐old woman, who was known to have acrodermatitis continua of Hallopeau, presented with a flare of her disease over her hands and a 2‐month history of development of pustular lesions over keloids located on her pre‐sternal area. Her disease had started 2 years previously on the left fourth finger, and had gradually progressed to involve other fingers. Keloids on her chest had arisen spontaneously without any preceding trauma 5 years previously. She was being managed with topical steroids and dapsone (100 mg oral tablet) daily, with partial response. On examination, there were erythematous scaly plaques studded with pustules on the fingers, and there was tapering of the fingers. Some of her fingernails had fallen off following the coalescence of pustules and formation of lakes of pus on the nail bed. Besides the pustules over the keloids, a few pustules and some erythema were seen at the periphery of the keloids (Fig. 1). No other site besides the hands and chest were involved. Histopathology of the pustular lesions over keloids was consistent with pustular psoriasis (Fig. 2).