A RASH FROM PROGESTERONE, ESTROGEN, OR IRON: OCPs HAVE THEM ALL BUT WHO'S TO BLAME

Abstract

Introduction Progesterone hypersensitivity (PH) is a poorly understood condition that was initially thought to be secondary to premenstrual progesterone exposure. However, few cases have been reported to exogenous sources of progestogens. We present a case of PH secondary to the use of a combined oral contraceptive pill (OCP). Case Description 18-year-old female with history of anxiety reported a maculopapular non-pruritic rash on her neck and chest, throat closing sensation, and chest tightness after completing a 6-week treatment with a combined OCP ordered by her gynecologist for contraception. The medication contained ferrous fumarate, ethinyl estradiol, and norethindrone acetate. Symptoms resolved within 3 days of treatment with diphenhydramine. Physical exam was noncontributory. Skin testing for the different components of the medication was performed. Testing was positive for progesterone (intradermal [0.005 mg/mL]), ferrous fumarate (intradermal [6 mg/mL]), and combined OCP (intradermal [pill dissolved in 1 mL]). The patient was advised to avoid these medications and to use estrogen-only contraceptive methods. Four months later, the patient was required to start iron replacement therapy due to anemia. An open oral challenge to iron-containing multivitamin was performed without adverse reactions. Discussion There are different sources of progestins including oral and implantable contraceptives, long-acting depot preparations, emergency contraception, and intrauterine devices. Exogenous sources of progestogens are an important and growing consideration in diagnosing PH. Progesterone skin testing has not been validated; a negative result does not exclude PH.