The cause of the condition is unknown. The disease is characterized by non-caseating granulomatous inflammation. That is, the granulomas do not undergo the caseating ("cheese-like") necrosis typical of the granulomas of tuberculosis. There is disagreement as to whether<unk>  represents an early form of Crohn disease or sarcoidosis, or whether it is a distinct, but similar clinical entity. Crohn disease can affect any part of gastrointestinal tract, from mouth to anus. When it involves the mouth alone, some authors refer to this as "oral Crohn disease", distinguishing it from<unk> , and others suggest that<unk>  is the same condition as Crohn disease when it presents in the oral cavity.<unk>  may represent a delayed hypersensitivity reaction, but the causative antigen(s) is not identified or varies form one individual to the next. Suspected sources of antigens include metals, e.g. cobalt, or additives and preservatives in foods, including benzoates, benzoic acid, cinnamaldehyde, metabisulfates, butylated hydroxyanisole, dodecyl gallate, tartrazine, or menthol, Examples of foods which may contain these substances include margarine, cinnamon, eggs, chocolate or peppermint oil. Some suggest that infection with atypical mycobacteria could be involved, (paratuberculosis), and that<unk>  is a reaction to mycobacterial stress protein mSP65 acting as an antigen. In response to an antigen, a chronic, submucosal, T cell mediated inflammatory response occurs, which involves cytokines (e.g. tumor necrosis factor alpha), protease-activated receptors, matrix metalloproteinases and cyclooxygenases. The granulomas in<unk>  form in the lamina propria, and may form adjacent to or within lymphatic vessels. This is thought to cause obstruction of lymphatic drainage and lymphedema which is manifest as swelling clinically. There may be a genetic predisposition to the condition. People who develop<unk>  often have a history of atopy, such as childhood asthma or eczema.
Orofacial granulomatosis
Cutaneous lupus mucinosis
Pemphigus erythematosus
Atopic dermatitis
Drug-induced angioedema
Streptococcal intertrigo
Drug-induced urticaria
Pemphigus