Orofacial granulomatosis (OFG) is a condition characterized by persistent enlargement of the soft tissues of the mouth, lips and the area around the mouth on the face, causing in most cases extreme pain. The mechanism of the enlargement is granulomatous inflammation. The underlying cause of the condition is not completely understood, and there is disagreement as to how it relates to Crohn's disease and sarcoidosis. Signs and symptoms may include: Persistent or recurrent enlargement of the lips, causing them to protrude. If recurrent, the interval during which the lips are enlarged may be weeks or months. The enlargement can cause midline fissuring of the lip ("median cheilitis") or angular cheilitis (sores at the corner of the mouth). The swelling is non-pitting (c.f. pitting edema) and feels soft or rubbery on palpation. The mucous membrane of the lip may be erythematous (red) and granular. One or both lips may be affected. Oral ulceration (mouth ulcers) which may be aphthous like, or be more chronic and deep with raised margins. Alternatively, lesions similar to pyostomatitis vegetans may occur in OFG, but this is uncommon. "Full width" gingivitis (compare with marginal gingivitis). Gingival enlargement (swelling of the gums). Fissured tongue (grooves in the tongue). Enlargement of the mucous membrane of the mouth, which may be associated with cobblestoning and mucosal tags (similar lesions often occur on the intestinal mucosa in Crohn disease). Enlargement of the perioral and periorbital soft tissues (the tissues of the face around the mouth and the eyes). The facial skin may be dry, exfoliative (flaking) or erythematous. Cervical lymphadenopathy (enlarged lymph nodes in the neck). Facial palsy (weakness and altered sensation of the face). The enlargement of the tissues of the mouth, lips and face seen in OFG is painless. Melkersson–Rosenthal syndrome is where OFG occurs with fissured tongue and paralysis of the facial nerve. The cause of the facial paralysis is thought to be caused by the formation of granulomas in the facial nerve, which supplies the muscles of facial expression.