Medical Dictionary

cold sore


Medical Definition of COLD SORE

:  a vesicular lesion that typically occurs in or around the mouth, that initially causes pain, burning, or itching before bursting and crusting over, and that is caused by a herpes simplex virus which remains dormant in the body and may be reactivated by a variety of factors (as stress, fever, or sunburn)—called also fever blister; compare canker sore


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