[Vulvar contact dermatitis due to seminal allergy: 3 cases]

Contact sensitivity deserves to be assessed in acute vulvitis as well as chronic vulvar dermatitis with a specific orientation toward semen allergy whenever the pathology is post-coital.

Three observations of semen allergy are reported. Two women presented with post-coital vulvitis due to delayed hypersensitivity to semen proteins without associated specific IgE. The type 2 allergy was confirmed by positive patch-tests and disappearance of symptoms when using condoms. Another woman presented with oedematous vulvitis associated with asthma and malaise per and post-sexual intercourse. Positive prick-tests with husband's semen and blood tests for specific IgE led to the diagnosis of type 1 hypersensitivity to semen, with disappearance of both vulvar and systemic symptoms with the use of condoms.

Immediate or delayed type hypersensitivity may be discovered using prick and patch tests respectively. The observation of vulvitis or vulvar discomfort should promote such investigations, whenever a post-coital chronology is suggested. The good clinical pertinence of positive skin tests must be emphasized. Although type I hypersensitivity to semen is documented in the literature, with easy detection of specific IgE, delayed type 2 allergy presents as an as yet under-diagnosed etiology of post-coital vulvitis. Patch tests may help to confirm that contact dermatitis may be due to seminal proteins.