Cutaneous hypersensitivity reactions to vitamin K: 2 case reports and a review of the literature.

Between 1964 and 1994, at least 52 patients with cutaneous adverse effects of vitamin K have been described in the European and North American literature. A review of the details of these patients is given and 2 new cases reported. Adverse effects are seen not only in patients with liver-function disturbances but also in patients without liver diseases, and occur mostly after intramuscular or subcutaneous administration of vitamin K1, independent of the total dose. Patch and intracutaneous tests often give positive reactions. The mechanism of action is probably in many patients a delayed-type hypersensitivity reaction.