Oral mucosal fixed drug eruption: characteristics and differential diagnosis

Little is known about the characteristic features of oral mucosal fixed drug eruption (FDE).

To present the clinical highlights and the differential diagnosis of oral mucosal FDE in a relatively large group of patients from Turkey.

This was a methodological, retrospective, cross-sectional study of 61 patients with oral mucosal FDE. The causative drug was established mainly by oral provocation test.

The age range of 61 patients (38 females, 23 males) was 7 to 62 years. Naproxen and cotrimoxazole were the main inducers. Fourteen patients (23%) had a solitary oral lesion predominantly located on the dorsum of the tongue, or on the hard palate, the former statistically significantly associated with cotrimoxazole. Bullous/erosive (n = 47), aphthous (n = 12), and erythematous (n = 2) morphology were observed. A considerable number of patients were referred with a prior clinical diagnosis of herpes simplex and Behçet's disease; some of them were already receiving long-term treatment with acyclovir and colchicine, respectively.

The main limitation of the present study resides in its retrospective design.

Isolated oral lesions, aphthous lesions, severe bullous/erosive lesions, and the absence of residual pigmentation are the main features that may cause difficulties in the differential diagnosis. It is important to differentiate dysmenorrhea-related monthly attacks of oral FDE in female patients caused by nonsteroidal anti-inflammatory drugs from menstruation-triggered attacks of herpes simplex infection, and isolated orogenital aphthous FDE from Behçet's disease, especially in countries with a high frequency of the disease in order to prevent irrelevant therapies.