![](https://cdn.healthyhabits.care/wp-content/uploads/2019/04/2-rash.jpg)
A rash
One of the first signs of mono is if you develop a rash after taking an antibiotic commonly used to treat a sore throat, such as amoxicillin or ampicillin. “These antibiotics are used when a bacterial cause of a sore throat is suspected, prior to the healthcare provider knowing that mono is present. The rash is not an allergic reaction,” says Dr. Danoff.