The symptoms usually last one to two weeks. The diagnosis of primary herpes is most often made on clinical history and presentation. Patients with ANUG also present with a sudden onset of a sore mouth. In individuals with primary herpes manifesting multiple oral ulcerations, aphthous stomatitis must be considered in the diagnosis. However, primary herpes can be distinguished from aphthous stomatitis by lesion location and history.
Aphthous ulcers occur only on mobile or unattached mucosa and there is a history of recurrence.
In contrast, primary herpetic lesions occur on both mobile and attached mucosa and there is no history of previous episodes. Most patients with aphthous stomatitis do not have systemic symptoms such as fever. Complications are unusual. Herpes keratitis if not properly treated can lead to blindness over time. After one has been infected with the herpes simplex virus, it remains latent in the body.