Why can allergies be treated with antibiotics?

I don't think they can??? In fact, antibiotics often are the cause of an allergic reaction. An "allergy" is when the body incorrectly thinks a harmless substance is a harmful substance. The body produces antibodies. Common items that people are allergic to are pollen (grass, tree), animal hairs (cats), foods (nuts), and antibiotics (penicillin). Antibiotics are for treating bacterial infections. Common medications to treat Allergies are antihistamines and steriods. Maybe someone else can offer an example?