Introduction
Demographics
Causes
Clinical features
Complications
Diagnosis
Differential diagnoses
Treatment
Outcome
Semen contact allergy is a rare but notable form of allergic contact urticaria that occurs during or after contact with seminal fluid.
It is also known as human seminal plasma allergy, seminal plasma hypersensitivity, or seminal fluid hypersensitivity.
The true prevalence of semen contact allergy in the general population is unclear. Less than 100 well-documented cases exist in the medical literature worldwide, however, the condition is likely underreported due to its sensitive nature. A survey of 1073 symptomatic women in the United States suggested a probable prevalence of around 8%.
The cause of semen contact allergy is unclear. Various authors of case studies have hypothesised that disruption of the normal female genital-tract immunomodulation may occur through:
A systemic reaction to semen is typically due to type I (immediate) hypersensitivity with subsequent development of IgE antibodies against proteins in human seminal fluid. Multiple allergens may be involved. Prostate-specific antigen, a 33–34 kD glycoprotein, is believed to play an integral role. It has been postulated that a highly cross-reactive protein in dog dander might be responsible for sensitisation, explaining how women may present after their first sexual intercourse.
In contrast to a systemic response, a localised reaction does not appear to involve IgE. While there have been occasional reports of type III (immune-complex) reaction and a fixed cutaneous eruption, the underlying immune mechanism of most localised semen contact allergy is unknown.
Allergy to seminal fluid may present as a localised reaction or a systemic response. Symptoms are fully prevented by the use of condoms.
A review of semen contact allergy case studies reported that:
Additional case studies describe repeated exacerbations of asthma after intercourse and a systemic reaction after topical contact with seminal fluid.
The localised reactions to semen contact allergy include:
The systemic reactions to semen contact allergy include:
Symptom resolution typically occurs within 24 hours, although localised vulvovaginal pain, urticaria, and malaise may persist for several days to weeks. Increasing intensity of reaction with subsequent exposures is a common feature.
After the initial onset, symptoms usually arise with all subsequent contact irrespective of the partner. However, the occurrence may be restricted to a specific partner.
Complications of semen contact allergy include the emotional impact on the individual and their relationships, resulting in anxiety and sexual dysfunction, and concerns about conception and pregnancy.
Diagnosis is often based on clinical history alone. The following investigations are undertaken to rule out other causes of symptoms.
Investigations to confirm semen contact allergy may include a skin prick test using seminal fluid proteins obtained from the patient’s sexual partner.
Serum-specific IgE antibodies to whole seminal fluid or fractionated seminal plasma proteins are found in all women with systemic reactions but are not consistently detected in those with localised reactions.
Other conditions that should be considered in a patient with symptoms suggestive of semen contact allergy may include:
General management of semen contact allergy may include:
Specific management of semen contact allergy may include:
Subcutaneous desensitisation using relevant seminal plasma proteins eliminates symptoms in > 95% of women over time. Women must be exposed to semen at least two to three times weekly to maintain tolerance.
Those with localised reactions tend to have more variable treatment outcomes. Neither form of semen contact allergy has been associated with infertility. Despite this, the condition may place an inordinate strain on any relationship.
