What is the common cause of lesions that are painful and appear on attached gingiva?

The primary herpetic stomatitis is characterized by the presence of painful lesions that most commonly affect the attached gingiva, in addition to the oral mucosa. This condition is caused by the Herpes Simplex Virus (HSV), typically HSV-1, and can present with multiple vesicular lesions that quickly ulcerate, leading to significant discomfort and pain.

Patients often experience initial symptoms like fever and sore throat along with the oral manifestations during the primary outbreak, which may occur in children or young adults who have not been exposed to the virus previously. The lesions can be quite painful due to the location on the gingiva and the irritation that occurs during normal activities such as eating and speaking.

While trauma can cause lesions, it is not a common cause specifically linked to painful lesions on attached gingiva. Candida infections primarily lead to white patches and do not typically manifest as painful lesions on the gingiva itself. Herpes simplex virus indeed also causes lesions, but the specific context and prevalence of lesions referenced in primary herpetic stomatitis clarify why this is the most appropriate answer.