More information about text formats
The publication of a clinical case in the BMJ Case Report on March 8 , entitled "Anaphylaxis probably induced by transfer of amoxicillin via oral sex", has resulted in interest in social networks, local and national press, radio, and television, reporting with big headlines of such allergic reaction, but without contrasting the work assessing the scientific content and experimental support.
The article reports the case of a woman with a history of allergy to penicillin in childhood who, after having sexual intercourse (vaginal and oral) with her partner, who was being treated for otitis media with amoxicillin/clavulanic acid and ibuprofen, presents dyspnea, vomiting, and urticaria. The patient had not ingested any unusual food. She was diagnosed with anaphylaxis probably induced by amoxicillin/clavulanic acid transfer in the seminal fluid of the couple through oral sex. This diagnosis was based solely on a skin reaction suffered in her childhood after taking amoxicillin (no description of how that diagnosis was made) and a probability algorithm . No allergological investigation was conducted at the time of the reaction.
Previous studies have shown that seminal fluid can serve as a route of transmission of ingested allergens, such as nut proteins , and drugs such as vinblastine , and penicillin . The latter study was the only one in which intradermal tests with penicillin, with a positive result, and intra-epidermal tests with semen, w...
Previous studies have shown that seminal fluid can serve as a route of transmission of ingested allergens, such as nut proteins , and drugs such as vinblastine , and penicillin . The latter study was the only one in which intradermal tests with penicillin, with a positive result, and intra-epidermal tests with semen, with a negative result, were carried out. In addition, seminal fluid-specific IgE levels were also determined, with a negative result .
In the present case, a relevant allergological study was not carried out at the time of the reaction in order to confirm the amoxicillin/clavulanic acid sensitization described by the patient, including in vivo and in vitro tests (skin tests, specific IgE levels or provocation tests to -lactam antibiotics). From the skin reaction after amoxicillin ingestion in childhood, it could be speculated that the patient is allergic to penicillins. However, this speculation has little experimental support. In the experience of most allergists, the cutaneous reactions produced in childhood, coinciding with the taking of penicillins, are usually infectious rashes. Neither skin tests nor determination of specific IgE to the semen have been carried out to rule out seminal plasma hypersensitivity (SPH) which, despite being a rare phenomenon, is more prevalent than the allergic reaction by drug transfer (amoxicillin), so it is necessary to rule out such a possibility . It would also be necessary to rule out postcoital asthma or food allergy (it is not excluded that she has previously tolerated a food) through an in vivo and in vitro allergological study that includes the assessment of serum tryptase levels, other types of acute urticaria and even microorganisms, which in this case has not been investigated .
Although the prevalence of SPH is unknown, we believe that this pathology may be underdiagnosed. Currently, around 100 cases have been documented in the English literature, being more frequently between 20-30 years and occurring at first sexual intercourse in 40-50% of patients . According to a survey conducted in 1997 to 1,073 US women, between 20,000-40,000 patients could suffer SPH (1/5,000) .
In Spain, the Allergy Unit of the General University Hospital of Elda published in 1993 the first case of immediate SPH, demonstrated by skin tests and determination of specific IgE positive to seminal plasma . In December 2017, we published a second case of local SPH which, in turn, was the first case of local SPH with colposcopic and histopathological control after postcoital vulvovaginal exposure, as well as local manifestations (contact urticaria) after oral sex . This work was the first case published in the literature of SPH demonstrated by genital biopsy and the first documented case of allergy to seminal fluid by oral sex. We also want to highlight the work carried out by Basagaña et al. describing the prostatic specific antigen (PSA) as one of the allergens that is sometimes responsible for SPH due to the cross-reactivity with Can f 5 allergen of dogs .
Therefore, it is desirable that scientific journals are keen to verify that published articles are supported by scientific evidence and solid experimental results, which make the "probable allergen" involved in the described allergic reaction very likely to be the "real allergen". This must always be taken into account, but even more so when the topic is very attractive for the general media to take the published information to look for eye-catching and sensational headlines. Of course, all the aforementioned information does not exclude that the allergic reaction was produced by amoxicillin transfer through the semen, but obviously it is necessary to have more experimental evidence to suggest it with certain guarantees of success. Articles should not be left in simple explanatory hypotheses without sufficient experimental evidence to support them.
1. Gomez Caballero N, Almenara S, Tevar Terol A, Horga de la Parte JF. Anaphylaxis probably induced by transfer of amoxicillin via oral sex. BMJ Case Rep. 2019;12.
2. Naranjo CA, Busto U, Sellers EM, Sandor P, Ruiz I, Roberts EA, et al. A method for estimating the probability of adverse drug reactions. Clin Pharmacol Ther. 1981;30:239-45.
3. Bansal AS, Chee R, Nagendran V, Warner A, Hayman G. Dangerous liaison: sexually transmitted allergic reaction to Brazil nuts. J Investig Allergol Clin Immunol. 2007;17:189-91.
4. Paladine WJ, Cunningham TJ, Donavan MA, Dumper CW. Letter: Possible sensitivity to vinblastine in prostatic or seminal fluid. N Engl J Med. 1975;292:52.
5. Green RL, Green MA. Postcoital urticaria in a penicillin-sensitive patient. Possible seminal transfer of penicillin. JAMA. 1985;254:531.
6. Shah A, Panjabi C. Human seminal plasma allergy: a review of a rare phenomenon. Clin Exp Allergy. 2004;34:827-38.
7. Nusair B, Gallagher E, Purohit P, Chye Gooi JH, Hamoda H. Seminal fluid hypersensitivity: A case report and review of the literature. Current Women's Health Reviews. 2018;14:81-6.
8. Resnick DJ, Chen L, Low J, Lee-Wong MF. Seminal plasma hypersensitivity and successful intravaginal graded challenge. Internet J Asthma Allergy Immunol. 2014;10.
9. Bernstein JA, Sugumaran R, Bernstein DI, Bernstein IL. Prevalence of human seminal plasma hypersensitivity among symptomatic women. Ann Allergy Asthma Immunol. 1997;78:54-8.
10. Jover Cerdá V, Parera M, Valera AC. Hipersensibilidad al fluido seminal humano: Presentación de un caso. Rev Esp Alergol Inmunol Clin Supl. 1993;8:223-7.
11. Jover Cerdá V, Rodríguez Pacheco R, Doménech Witek J, Durán García R, Garcia Teruel MJ, Santes García J, et al. Seminal plasma hypersensitivity: Clinical and histopathologic features in a multipara woman. J Allergy Clin Immunol Pract. 2017;5:1768-70.
12. Basagaña M, Bartolomé B, Pastor-Vargas C, Mattsson L, Lidholm J, Labrador-Horrillo M. Involvement of Can f 5 in a case of human seminal plasma allergy. Int Arch Allergy Immunol. 2012;159:143-6.