An acute or chronic gingivitis characterized by redness and swelling, necrosis extending from the interdental papillae along the gingival margins, pain; hemorrhage, necrotic odor, and often a pseudomembrane. The condition may extend to the ORAL MUCOSA; tongue; palate; or pharynx. The etiology is somewhat unclear, but may involve a complex of fusobacterium nucleatum along with spirochetes borrelia or treponema.