[Acquired angioneurotic edema induced by hormonal contraception]

Although frequently pointed out in the aetiology of chronic angioedema or chronic abdominal pain, food allergy is frequently a diagnosis for lack of anything better, as exemplified by disappointing results of eviction regimens. This has resulted in the search for other aetiologies, such as an iatrogenic effect of oral contraceptives.

Detailed medical history was obtained on 38 young women, aged a mean of 26 years, experiencing chronic angioedema initially ascribed to food hypersensitivity, but in whom a deficit in C1 inhibitor was demonstrated. We investigated the effects of oral contraception on their level of C1-INH, functional C1-INH assay and their clinical symptoms.

An interruption of oral contraception induced an increase of the C1-INH level from 0.201 to 0.224 g/L (p < 0.002) and of the C1-INH functional assay fom 0.396 to 0.702 U (p < 0.0001), associated with a recovery or a marked improvement of the clinical symptoms formerly ascribed to food allergy. The replacement of the initial contraception containing ethinyloestradiol by a progestogen maintained or even improved their clinical and biological state.

Exogenous estrogen such as those contained in most oral contraceptive may play an iatrogenic role in the aetiology of chronic angioedema.