What can my daughter take to relieve symptoms of nylon allergy?

Avoidance only way: If you are referring to a contact dermatitis rash on exposure avoidance is the only effective prevention. Acutely steroids can lessen the symptoms, but have significant side effects. There is no desensitization for this type of allergic reaction.

Simple: Any histamine pill depands on age of the pt and use mild otc Hydrocortisone cream , some times natural aloe gel works . Ofcourse no nylon