Type IV hypersensitivity to vitamin K

Abstract The day after intramuscular injection of vitamin K1 (phytomenadione) into her thigh, a 27-year-old-woman with normal liver function developed a relapsing and remitting eczematous reaction localized to the injection site, and later a further eczematous reaction under an adhesive dressing (Duoderm). On patch testing, she was positive to vitamin K1 and cross-reacted to vitamin K4; she was also positive to colophonium and to ester gum rosin, the dressing adhesive. Recurrent angioedema persisted for several months and, 2 years later, symptoms were still occurring over the injection sites. Structure-activity relationships among vitamin K allergens are discussed.