Gallbladder edema in type 1 diabetic patient due to delayed-type insulin allergy.

A 29-year-old woman was diagnosed as having type 1 diabetes mellitus and received insulin aspart and NPH insulin (Novolin®N). On day 22, she had leg edema and right abdominal pain. The serum hepatobiliary enzyme levels were markedly elevated. Computed tomography revealed gallbladder edema. After an injection of human regular insulin and NPH insulin (Humacart®N), the elevated liver enzyme levels were no longer observed. Challenge testing demonstrated that protamine was the cause of her allergy. Furthermore, tests revealed increased VEGF levels. This is an extremely rare case with a delayed-type protamine allergy caused by Novolin®N resulting in gallbladder edema.