I need a scientific explanation for a experienced phenomenon.

I have a house dust mite allergy and because of it my nose is almost always stuffed and blocked when i lie in bed and it's hard to breathe.

BUT everytime I decide to masturbate while lying in said bed my nose gets suddenly unblocked and it's like i don't have any allergy at all.

How come? What is the possible reason for it? How does masturbating effect allergy symptoms?