Curriculum · ENT, Ophthalmology, and Dermatology
Orolabial herpes simplex infection
What it is
Herpes simplex virus type 1 is the one that settles about the mouth and nose, and on the lip it carries the name herpes labialis. It shows as herpetic gingivostomatitis, as cold sores and as fever blisters. The virus does not leave: it stays latent and dormant in the trigeminal ganglion, and what comes later is a reactivation of it.
How it presents
The lesion is painful, grouped vesicles on an erythematous base that go on to ulceration. On the lip these are the cold sores and fever blisters. In the mouth the picture is herpetic gingivostomatitis, with vesicles that ulcerate. Perioral vesicles in the past history are the mark of an earlier primary infection, and a recent immunosuppression or illness often comes before it.
How it is diagnosed
A Tzank smear, PCR and direct fluorescent antibody are the tests used for herpes simplex.