Tacrolimus is used on the skin to treat a skin condition called eczema (atopic dermatitis) in patients who have not responded well to (or should not use) other eczema medications.
Eczema is an allergic-type condition that causes red, irritated, and itchy skin. This drug works by weakening the skin's defense (immune) system, thereby decreasing the allergic reaction and relieving the eczema. Tacrolimus belongs to a class of drugs known as topical calcineurin inhibitors (TCIs).
Tacrolimus  is an immunosuppressive drug whose main use is after organ transplant to reduce the activity of the patient's immune system and so the risk of organ rejection. It is also used in a topical preparation in the treatment of severe atopic dermatitis, severe refractory uveitis after bone marrow transplants, and the skin condition vitiligo.