IGHE and anaphylaxis: In progestogen hypersensitivity, typically occurring in women in childbearing years with a spectrum of symptoms ranging from dermatitis, urticaria to anaphylaxis, associated with exogenous progestin exposure (contraceptive medicines, in vitro fertilization therapy) or endogenous progesterone from progesterone surges during the luteal phase of the menstrual cycle and pregnancy, the most commonly accepted mechanism is IgE-mediated sensitization.