Dermatitis herpetiformis and gluten sensitive enteropathy (including celiac disease)--increased subepithelial extracellular matrix viscosity due to gliadin

Pellagra--increased viscosity of extracellular matrix

Pellagra is the result of increased viscosity of extracellular matrix (ECM). The skin changes in pellagra localize at sites of sun exposure or trauma because the mediators which are released cannot diffuse from the area. Edema is reported as the first clinical and microscopic change. Changes in the ECM are not directly visible. Increased viscosity of ECM in the gastrointestinal tract would decrease absorption of fluid and nutrients from the bowel resulting in diarrhea. In the tongue the excess ECM viscosity holds water producing swelling. The effect of climate and seasons relates to the increased demand for ECM repair on sunlight exposed areas. Infections increase the severity of pellagra by requiring increased tissue repair. Local infections are often unusually severe. Infections have a greater inflammatory component at sites of high ECM viscosity. Nicotinic acid reverses the neurologic and gastrointestinal changes of pellagra in 24 h. This suggests a simple rapid mode of action. Nicotinic acid plays a major role in tissue respiration which is essential for tissue repair and degradation of glycosaminoglycans. Altering ECM viscosity is a method of modulating inflammation, immunity, and normal tissue physiology.

Aphthous stomatitis (canker sores): a consequence of high oral submucosal viscosity (the role of extracellular matrix and the possible role of lectins)

Recurrent aphthous stomatitis (RAS) or canker sores occur in 20-60% of all persons. The lesion occurs because of increased viscosity of oral submucosal extracellular matrix (ECM). The lesions begin in the second decade and peak in the third decade. Sex hormones are an important influence on fibroblasts, especially in the early phase of exposure. Sex hormones are known to concentrate, to a degree, in the bucal mucosa in animals. Lesions of RAS localize clinically and experimentally at sites of trauma. In the skin, edema is known to trigger early cellular inflammation. Increased viscosity of ECM heightens the response. The histopathology of the ulcerated lesions is similar to that which occurs under sites of acute inflammation in the skin. Systemic corticosteroids completely supress the lesions. Caustics, such as silver nitrate and phenol, stop the growth and pain of lesions. Irritants are known to break ECM viscosity. The oral mucosa exerts some control on underlying ECM. Substances such as lectins influencing the mucosa could influence ECM. Soluble substances in food or organisms could also penetrate to influence ECM. A number of different foods have been incriminated as trigger agents in individual cases. This includes gluten in patients with gluten sensitive enteropathy. Gluten is known to alter the mucosa of the small intestine in persons with celiac disease.