It's not possible to ACTUALLY be allergic to sex, but you CAN react to products or secretions that come into play DURING sex. If you're allergic to certain fragrances, chemicals and animal proteins, you may develop hives, rashes and blisters, if these exist in any lubricants or serums.The latex CONDOM is another potential allergy trigger, possibly causing hives, congestion, genital swelling and for some, anaphylaxis, or shock. Although a latex allergy affects less than 1 percent of the population, if you have it, there are latex alternatives such as polyisoprene or polyurethane condoms. Interestingly, foods such as avocados, bananas, chestnuts, kiwis and passion fruits also contain some of the SAME allergens found in latex. Traces of these food allergens can ALSO show up in your male partner's semen, which means if you are allergic to latex you may ALSO have a reaction to semen. There are also cases in which a woman has an allergic reaction to a man's semen itself. A study from the University of Cincinnati found that half of the women who had a semen allergy suffered from hay fever and skin allergies. To find out what exactly is causing your allergic reactions; doctors will recommend either a skin or blood test, focusing on latex and food allergies. If it turns out you're allergic to either, a medication may be prescribed.But if the allergy is actually to semen, you may need to try desensitization. This involves controlled exposure over the course of several weeks to hopefully help reset your immune response. For more information on diagnosing and treating allergies, check out other videos on this site.