Avoid physical contact with anyone who has visible blisters and sores, and don't share towels or anything that may have come into contact with the sores. "It is also important that before you have any intimate contact with anyone you ask them about their sexual health, whether they have a herpes infection or have ever had any other sexually transmitted infection," Michael advises. "This is because statistically, people who have had an STI are more likely to be infected with the herpes virus. Using condoms and dental dams can also help reduce your risk of catching oral herpes."
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.
A 2004 study in the New England Journal of Medicine found that suppressive therapy decreases the risk of HSV-2 transmission from symptomatic, infected partners to uninfected partners by 48%. So “the risk of transmission is significantly reduced, but cannot be eliminated even with suppressive therapy,” Johnston explains, and she stresses that the virus can be passed along even without signs or symptoms.