Autoimmune progesterone dermatitis (APD) is an immune reaction to endogenous progesterone that can follow exposure to exogenous progesterone. Skin eruption develops cyclically during the luteal phase of the menstrual cycle when progesterone levels are elevated. Patients present with a variety of skin eruptions, including erythema multiforme, eczema, urticaria, angioedema, and progesterone-induced anaphylaxis.
The resultant clinical symptoms are frequently confused with other forms of dermatosis. The diagnostic criteria of APD include recurrent cyclical worsening of skin lesions and symptomatic improvement after inhibition of progesterone secretion by suppression of ovulation. The pathogenesis is unclear. Diagnosis is confirmed by skin testing for inflammatory responses to small doses of the hormone, and desensitization with small doses of the hormone is the most appropriate form of management.