Acute systemic hypersensitivity reactions to semen are rare but may be life-threatening. Chronic or recurrent local reactions are more common and may be misdiagnosed as infective or nonspecific vaginitis. The antigen(s) involved in these reactions reside in a glycoprotein fraction of seminal plasma. Allergic vulvovaginitis may also occur in sensitized women when they are exposed to exogenous allergens such as drugs, food and infective agents during sexual activity. Skin testing and other relevant investigations are indicated when these disorders are suspected. Condom usage will prevent symptoms of coital allergy. Desensitization has had variable success in acute systemic hypersensitivity. Precoital antihistamines may modify local reactions.
PIP: The focus of this study on coital allergy is on discussing the basis for and clinical implications of the immunological reactions that mediate allergic reactions to semen. Allergic reactions to antigens in seminal plasma occur in the case of acute systemic hypersensitivity (ACH), localized postcoital allergic seminal vulvovaginitis, and/or hypersensitivity to exogenous allergens in semen. In the few cases (30 cases at present), ACH may manifest itself in generalized urticaria, orbital and vulval edema, vulval and generalized pruritus, bronchospasm, lower abdominal pain, hypotension, and loss of consciousness. There may be a family history of atopy. Symptoms may appear over months or years before reaching a severe level. The usual case is the appearance after the 1st coital act or after a change in coital, genital, or reproductive occasions. It is not specific to a particular male partner. It may be self-limiting. Condom usage or abstinence may lead to abatement. Localized vulvovaginitis may occur simultaneously with ACH or exist alone. The symptoms are local pruritus, burning, swelling, erythema, and urticaria in varying degrees for up to a week and occur during or after coitus. Douching or vulval irrigations may ameliorate symptoms. Misdiagnosis as genital herpes or infective vulvovaginitis may occur in mild cases. Exogenous allergens derived from drugs, food, and other sources presenting in the semen may contribute to hypersensitivity. This is different from reactions to intrinsic components of seminal plasma. Vaginal exposure to chemical products such as soaps or to airborne particles such as pollen may produce allergic responses. Another possibility is that genital candidiasis may produce local Ige antibodies, and PGE2 induced suppression of cell-mediated immunity. The immunological mechanisms are described as type I hypersensitivity reactions with the antigen reacting with reaginic antibodies of the Ige class which are bound to mast cell or circulating basophils. The antigens and the immune reactions are specified. In the clinical diagnosis, the rare acute systemic form is obvious, but the atypical, recurrent, and intractable forms of vulvovaginitis require investigation with skin tests. Treatment may involve artificial insemination for those seeking pregnancy, immunotherapy, or antihistamines, rather than use of a condom or abstinence.