Hypersensitivity reactions to parenteral vitamin K.
Cutaneous hypersensitivity reactions to vitamin K are rare.  They occur almost exclusively with fat-soluble vitamin K (K1).  The lesion is most commonly a pruritic, indurated plaque at the site where the vitamin was injected.  Most plaques resolve within 4 to 8 week without sequelae, but some progress to produce scar-like changes that may last for years.