Orofacial granulomatosis is an uncommon disorder that likely represents a hypersensitivity reaction. It was originally described as a triad of recurrent edema of the lips, recurrent facial nerve palsy, and a fissured or plicated tongue and given the eponym Melkersson-Rosenthal syndrome. Some sources consider recurrent orofacial edema, instead of just recurrent edema of the lips, as a defining criterion. The orofacial swelling most commonly involves the upper lip, followed by upper and lower lips, the circumoral, and periorbital tissues. The orofacial swelling in orofacial granulomatosis is characterized histologically by granulomatous inflammation. However, facial nerve palsy is uncommonly seen, and the fissured tongue is very common in the adult population. Thus many now question the use of this eponym if only lip swelling and fissured tongue are present. It has also rarely been reported on the vulva.

Orofacial granulomatosis is also known as cheilitis granulomatosa or granulomatous cheilitis and may be associated with hypersensitivity to some foods and food additives (in particular benzoates and cinnamon products), sensitivities to amalgam, Crohn disease, and sarcoidosis. If no specific etiology can be identified (eg, after patch testing or evaluation for systemic disease), the condition is deemed idiopathic. However, orofacial granulomatosis may be the first manifestation of Crohn disease, with gastrointestinal signs and symptoms occurring years later. 

Orofacial granulomatosis typically presents in the late second decade but has been reported in children as young as 5 years of age. Some studies demonstrate an increased incidence in females compared with males, while other studies do not show a difference. No ethnic predilection has been shown. Most patients first develop intermittent asymptomatic swelling of the lips. Eventually, the swelling becomes persistent. Rarely, patients develop facial palsy first. Other associated neurologic and ophthalmologic symptoms include migraine headaches, tinnitus, dizziness, vision disturbances, and excessive tearing. Involvement of the facial nerve by granulomas is what leads to facial nerve palsy.