Herpes?: A very common cause of sores on the lips (not inside like canker sores) is oral herpes ("cold sore", "fever blister"). As these names suggest, other infections like colds or strep throat can trigger herpes outbreaks in persons infected with type 1 herpes simplex virus (HSV1). Herpes is especially likely if it started like a blister or pimple. See a doctor ASAP to confirm diagnosis and Rx advice.
Answered 10/12/2015
2.2k views
4 doctors weighed in across 2 answers
2 doctors weighed in across 2 answers
4 doctors weighed in across 2 answers
A doctor has provided 1 answer
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question