It's clearly an infection of some sort; what's not clear is what kind.
Many infections would clear up on their own - others would not and could do serious damage. It is likely, and hopefully, the former - but if he likes his parrot he should do more than hope. He should have it checked out by a vet.
Has your friend changed detergents, or is your friend wearing too much perfume/cologne? Sounds like an irritation of some sort. I would watch the bird and if not better within 24 hours, hurry him/her along to an avian vet.