Fixed Drug Eruption Secondary to Four Anti-diabetic Medications: An Unusual Case of Polysensitivity.

We report a case of fixed drug eruption in a 58-year-old lady treated for diabetes with four pharmacologically different anti-diabetic agents that were used at separate times of therapy. Skin manifestations, including erythema, blisters, and ulcers, developed over the right leg each time after the initiation of metformin, gliclazide, vildagliptin, and empagliflozin; and disappeared following the discontinuation of the drugs. Magnesium stearate was the common excipient identified in the four agents. This is an extremely rare case of fixed drug eruption caused by structurally dissimilar drugs.