Imagine itching, burning, swelling, or even struggling to breathe just moments after sex. For a small but growing number of women, that’s not an awkward anecdote – it’s a medical condition. It’s called seminal plasma hypersensitivity (SPH) – an allergy to semen.
This rare but underdiagnosed allergy isn’t triggered by sperm cells, but by proteins in the seminal plasma — the fluid that carries sperm. First documented in 1967, when a woman was hospitalised after a “violent allergic reaction” to sex, SPH is now recognised as a type 1 hypersensitivity, the same category as hay fever, peanut allergy and cat dander.
