Allergies. Many of us have them. Dust, pollen, peanuts, strawberries, insect bites and stings; the list seems endless. In fact, it is much more extensive than you could imagine.

My professional research tool #1 (Google autocompletion) tells me that ‘allergic to ...’ is commonly followed by: alcohol, beer, bananas, condoms, chocolate, cold, everything, hair, Jaegermeister, jeans, ky jelly, kissing, latex, lube, (sun)light, snow, semen, sugar, urine, vegetables, vodka, water, xmas tree and yourself (examples may have been pre-selected for comedy value). It appears that people are often allergic to the things that are a) fun, b) attached to or present inside your own body and c) essential to life. But do these conditions really exist? Let’s take a look at some extreme and tragicomic examples: water and sperm.

Allergy to water, aquagenic pruritus, really does exist. Patients experience a skin rash when in contact with water, be it from baths, rain or sweat. Not much is known about the condition, there is no cure, and although treatments exist, they show varying effectiveness in reducing the symptoms. In an article about a female patient, the Daily Mail described another symptom as the ‘attraction of unwanted attention when wet’.

Allergy to semen in men, also known as Postorgasmic Illness Syndrome (POIS), has recently been more closelystudied in papers published in the Journal of Sexual Medicine. Patients suffer flu-like symptoms only minutes after orgasm. The cause of the symptoms was determined in a standard allergy test – the prick test. A sample of the substance thought to cause the allergy is applied to the skin and the skin punctured with a small needle to allow the substance to enter. This procedure has also been successfully used as a therapy for POIS, although it does involve being injected with your own semen for about three years. The scientists estimate that about 0.25 to 1% of the population may suffer some form of POIS, but most are undiagnosed as the condition is not well known, and many sufferers are embarrassed to seek help. I personally think that the thought of the therapy may also be somewhat offputting.

Allergy to sperm can also exist in women. Here it can cause skin rash, nausea, diarrhoea, asthma and anaphylactic shock. The condition in women has been studied more commonly than the condition in men. It is not clear why
this should be the case, but it has been suggested that a gender difference in the location of the rash may require more urgent treatment in women.

Lisa Görs is doing a PhD in Synthetic Biology at Imperial College London and is using Weevil to heal her work allergy.