sinusitis
"I went to a CVS walk-in clinic and was diagnosed with a sinus infection. Was prescribed amoxicillin/clav for 10-days. After 2nd day I started feeling better, but on the 9th day I developed a severe allergic reaction. Horrendous rash that spread all over my body. Terrible itching/burning. Wound up on prednisone and other drugs for 2 weeks to counteract the reaction to the antibiotic. Had no idea I was allergic so could not advise person at CVS, but it has been three weeks of hell."