Systemic contact dermatitis to foods: nickel, BOP, and more.

Systemic contact dermatitis (SCD), a cutaneous reaction that is a direct manifestation of systemic exposure to a known allergen in a sensitized individual, has been increasingly recognized as a cause of persistent cutaneous contact dermatitis that is refractory to conventional therapies. While SCD in response to drugs has been described well in the literature, SCD to allergens in common foodstuffs is a less well-articulated phenomenon. Several foods that are universally consumed throughout the world contain potent allergens including nickel, balsam of Peru, trace metals, urushiol, and sesquiterpene lactones as well as a host of others that may cause a distinctive clinical picture. In this review article, the authors review the typical presentation and prevalence of SCD to foods, pathophysiology, the most common offensive ingestible food allergens, several appropriate diets, and effectiveness of dietary avoidance for situations in which SCD is suspected.