Cephalexin Monohydrate I had an eye infection. I took Cephalexin for two days. Two days later my face broke out into this itchy, red rash. My face then got swollen and felt like sandpaper. It is horrible. It is slowly going away with some steriod cream given to me by a dermatologist. But today i noticed a rash on my neck as well. It is horrible! I wouldn't recommend ANYONE taking this medication!