Scald-Induced Necrobiosis Lipoidica in a Patient with Diabetes Mellitus and Psoriasis.

The Koebner phenomenon (KP) was first introduced by Heinrich Koebner in the 1870s to describe the appearance of psoriatic lesions following trauma in psoriasis patients. KP has since been defined in numerous diseases, including necrobiosis lipoidica diabeticorum (NLD). Since most Koebnerized dermatological lesions can localise to a site of previous trauma, Weiss et al. (Eur Acad Dermatol Venereol 2002;16:241-248) classified them into four categories (I-IV) according to the Boyd-Nelder classification (Int J Dermatol 1990;29:401-410) system. In this system, necrobiosis lipoidica is classified as category III, which includes diseases that occasionally localise at the site of trauma. We report a case of NLD that developed after scald in a psoriasis patient. NLD after trauma has often been reported, but this is the first case of NLD that coincidentally occurred at a scald site in a psoriasis patient.