A myriad of different phenomena exist in the dermatological literature which are based on the concept of locus minores resistentiae. The most commonly described phenomenon is the Koebner phenomenon, which is classically associated with the emergence of psoriatic lesions post trauma. Warfarin-induced skin necrosis (WISN) is a rare but severe side effect that leads to necrosis of the skin, predominantly on areas with increased subcutaneous fat. The presented case reports on WISN within psoriatic plaques.

With a prevalence of up to 20%, eczematous lesions are the most common skin adverse events of tumor necrosis factor alpha inhibitors. Eczematous lesions triggered by more modern biologics such as the IL17A antagonist secukinumab have been rarely reported. Herein, a case of secukinumab-induced pompholyx in a psoriasis patient is presented.