A Case of Progestogen Hypersensitivity

Progestogen hypersensitivity (PH) is a cyclical dermatosis that occurs in fertile women during the luteal phase of the menstrual cycle. The clinical presentation is variable and non-specific. We report the case of a 42-year-old woman with a 10-year history of itchy skin lesions that recurred monthly. Determined with her basal body temperature chart, her skin symptoms were related to progesterone surges. Skin examinations revealed multiple and extensive monomorphic red papules, mainly on her arms and legs, as well as on her chest and back. She had no history of associated fever or dyspnea. Her hair, nails and mucous membranes were normal. A blood test at the time of the worst skin eruption revealed mild elevation of serum thymus and activation-regulated chemokines and eosinophilia. Her total serum IgE level was normal. She showed a delayed skin reaction to progesterone. Ultra-low-dose combined oral contraceptives (COCs) improved her symptoms by suppressing ovulation. Accordingly, a diagnosis of progestogen hypersensitivity was made. A T-helper (Th)2 response rather than a Th1 response was suggested to be involved in this case. Atopic dermatitis (AD) can be classified into the major extrinsic type with high serum IgE levels and the minor intrinsic type with normal IgE levels. PH and AD share similarities in that they present with eczema, IgE-mediated sensitization and delayed hypersensitivity responses, and their pathophysiology remains to be fully elucidated because of their heterogeneous aspects. The symptoms of this case were in line with IgE-low AD rather than IgE-high AD, which implicates endogenous progesterone as a trigger.