Abstract

Vitamin K is a fat soluble vitamin used to treat or prevent certain coagulation disorders, because it is strongly required by the human organism for the production of the coagulation factors II, VII and X, and the dietary intake of the daily doses are strongly recommended to avoid the onset of bleeding and haemostasis disorders. However, Vitamin K is surely the vitamin for which majority of hypersensitivity reactions have been described for, either immediate or delayed-type, and sometimes the clinical manifestations do not allow the certain identification of the immune pathomechanism. Furthermore, the excipient like Cremophor EL i.e., polyoxyl 35-hydrogenated castor oil, plays a role in eliciting immediate type reactions, which can be pseudo allergic or IgE mediated even. Crempopor EL is in fact used as a suspending agent in many hydrophobic drugs like cyclosporine, tacrolimus, paclitaxel, teniposide and many others. On the other hand, vitamin K-induced delayed type reactions exhibit a wide range of morphological clinical pictures, mainly cutaneous. Patch tests and intradermal tests are very useful in delayed type reactions to diagnose such a hypersensitivity, while immediate reading skin tests have resulted doubtful or poorly helpful in the diagnosis of the immediate type reactions.