Terbinafine
"I used this on a tinea problem on my eleven year old. Initially it was extremely itchy, and I thought he was just being wimpy (shame on me as a parent), as he later developed a strong case of hives on the legs, which was exacerbated by swimming at a swimming pool. A strong red rash and hives resulted, before settling. He took an antihistamine tablet, with no further problems since."