Yes you can be allergic to sperm.
The sperm allergy is also known as a semen allergy.
Another term for sperm allergy or semen allergy is seminal plasma hypersensitivity which is a rare allergy to sperm.
The allergy is an allergic reaction to the protein that is in a mans sperm.
So yes some people can be allergic to a mans sperm which is normal but it's rare that a person is allergic to sperm.
If a woman is allergic to the sperm the sperm allergy in woman will show symptoms such as redness, swelling, pain, itching, and a burning sensation in the vaginal area.