Herpes symptoms commonly show in or around the mouth. Sores may also occur at the back of the throat, causing the lymph nodes in the neck to swell. Mouth herpes is very common in children, as their parents or relatives can pass it on to them easily by a greeting or goodnight kiss. To get a better understanding of oral herpes, let us take a look at its causes.
There are two types of herpes simplex virus, type 1 (HSV-1) and type 2 (HSV-2).[1] HSV-1 more commonly causes infections around the mouth while HSV-2 more commonly causes genital infections.[2] They are transmitted by direct contact with body fluids or lesions of an infected individual.[1] Transmission may still occur when symptoms are not present.[1] Genital herpes is classified as a sexually transmitted infection.[1] It may be spread to an infant during childbirth.[1] After infection, the viruses are transported along sensory nerves to the nerve cell bodies, where they reside lifelong.[2] Causes of recurrence may include: decreased immune function, stress, and sunlight exposure.[2][3] Oral and genital herpes is usually diagnosed based on the presenting symptoms.[2] The diagnosis may be confirmed by viral culture or detecting herpes DNA in fluid from blisters.[1] Testing the blood for antibodies against the virus can confirm a previous infection but will be negative in new infections.[1]
Traditionally, it was assumed that HSV-1 strictly caused oral sores and blisters, whereas HSV-2 caused genital and/or rectal sores and blisters. However, the virus- or perhaps just our understanding of the virus itself- has evolved in such a way that doctors now recognize that either HSV-1 or HSV-2 can cause genital and/or rectal sores, albeit with HSV-2 causing the majority of sores in the genital or rectal areas.

A doctor will base a presumptive diagnosis on information provided by the patient and on the physical examination. The characteristic appearance of the herpes sores leaves little doubt about the diagnosis, so the typical appearance of the sores is key to the diagnosis. This appearance helps distinguish oral herpes from oral thrush, shingles, gonorrhea, and syphilis. In addition, chapped or sunburned lips can resemble oral herpes, but the tissue stain (Tzanck smear, see below) shows no virus-induced cell changes. Further testing is usually not necessary but is sometimes done.

×