Inflammatory diseases of unknown etiology

Historically, many inflammatory diseases of unknown etiology have turned out to be caused by autoimmunity, genetic predisposition, allergy, neurodegeneration, or infection.

Research into inflammatory diseases of unknown etiology often starts with a study of the inflammation process to see if it provides any clues to the etiology of the disease. In general, there are two basic types of inflammation, acute and chronic. In acute inflammation the predominant cells involved are neutrophils. In chronic inflammation, the predominate cells involved are mononuclear cells, such as monocytes, macrophages, lymphocytes, and plasma cells.

Alzheimer's Disease
One review articles states, "Inflammation clearly occurs in pathologically vulnerable regions of the Alzheimer's disease (AD) brain, and it does so with the full complexity of local peripheral inflammatory responses. In the periphery, degenerating tissue and the deposition of highly insoluble abnormal materials are classical stimulants of inflammation." (PMID 10858586)

Adult-onset Still's disease
One article reports, " is a rare systemic inflammatory disease of unknown etiology, characterized by daily high, spiking fevers, evanescent rash, and arthritis."

Acute retinal pigment epitheliitis
Acute retinal pigment eptheliitis is one cause of sudden visual loss, often occurring in middle-aged men, but often with spontaneous recovery. The pathology is inflammation of the retinal pigment epithelium. It can occur in younger patients, sometimes associated with a viral illness. However, in most cases acute retinal pigment epitheliitis is an inflammatory disease of unknown etiology.

Tietze's Syndrome
Tietze's Syndrome is an inflammatory disease of the chest. According to once review article, "The disease has been characterized as a tender, non-suppurative swelling in the upper costosternal region. The etiology and pathology of the disease are still unknown."

Atherosclerosis
Atherosclerosis is inflammation of the blood vessels, or "hardening of the arteries." This clogging of the arteries is largely blamed on cholesterol. Atherosclerosis is a chronic inflammatory disease, in most cases initiated by hypercholesterolemia.

Behçet's Disease
Behcet's disease is an inflammatory disease of blood vessels. "The exact cause is unknown. It is believed that an autoimmune reaction may cause blood vessels to become inflamed, but it is not clear what triggers this reaction."

The White Dot Syndromes
The "White Dot Syndromes" are described in one review article as "a group of idiopathic multifocal inflammatory conditions involving the retina and the choroid. They are characterized by the appearance of white dots in the fundus."

Granuloma annulare
Granuloma annulare is an inflammatory disease of the skin, but the cause remains unclear.

Rheumatoid arthritis
Rheumatoid arthritis is an inflammatory disease of unclear etiology. As one review article says, "Rheumatoid arthritis (RA) is represents the most common chronic inflammatory joint disease and is still a major medical challenge because of unsolved issues related to the etiologic and pathogenetic questions." Rheumatoid arthritis involves T cell initiated inflammation.

Sjögren's Syndrome
According to the Merk Manuel, "Sjögren's syndrome is characterized by excessive dryness of the eyes, mouth, and other mucous membranes. Sjögren's syndrome is thought to be an autoimmune disorder, but its cause is not known. It is more common in women than in men. White blood cells infiltrate the glands that secrete fluids, such as the salivary glands in the mouth and the tear glands in the eyes. The white blood cells injure the glands, resulting in a dry mouth and dry eyes — the hallmark symptoms of this syndrome."

inflammatory bowel disease
These are diseases of unknown etiology characterized by inflammation of the colon.

Irritable Bowel Syndrome
Irritable bowel syndrome is by definition a disease of unknown etiology and it is associated with abdominal pain, bloating, diarrhea, and constipation. It is also associated with inflammation of the mucosal lining of the intestines.

Gastroenteritis
Gastroenteritis is frequently an inflammatory disease of unknown etiology. Often no diagnosis can be made between a pathogen caused gastroenteritis or symptoms caused by a food allergy. Often the cause simply remains unknown even when extensive testing is done. Gastroenteritis of unknown etiology is often deadly, suggesting the need for better and more rapid diagnostic techniques. One articles says, "Gastroenteritis of unknown etiology (GUE) is a significant cause of mortality in the United States." Bacterial gastroenteritis is characterized by polymorphonuclear white blood cells. Eosinophilic gastroenteritis also exists, which is characterized by infiltration of gastrointestinal tissue by eosinophils.

Graves' disease
is an inflammatory disease of unknown etiology that causes hyperthyroidism. The body incorrectly produces antibodies to the receptor for thyroid-stimulating hormone. These antibodies then stimulate thyroid hormone production. The trigger, if there is one, that starts the inflammatory process is unknown. A genetic predisposition may be present. Enteroviruses are not linked to the etiology of Graves' disease.

Multiple Sclerosis
Multiple sclerosis is an inflammatory disease of unknown etiology in which white blood cells, called T cells, attack parts of the central nervous system.

Psoriasis
According to Emedicine.com "Psoriasis is a ... skin disorder that most commonly appears as inflamed, edematous skin lesions covered with a silvery white scale." (http://www.emedicine.com/EMERG/topic489.htm) The inflammatory pattern of psoriasis involves T-cells.

Eczema
Eczema is a term used for inflammatory diseases of the skin. In fact, dryness and inflammation are hallmarks of eczema. One source says that "The most common type of eczema is atopic dermatitis." (http://www.nlm.nih.gov/medlineplus/eczema.html) Eczema is characterized by lymphocytic leukocytosis. (http://eczema.dermis.net/content/e01geninfo/e06histopathology/index_eng.html) The etiology of eczema remains unclear. One review article states: "Doctors do not know the exact cause of eczema." (http://www.medicinenet.com/eczema/article.htm#tocc).

Sarcoidosis
Sarcoidosis is an inflammatory disease of unknown etiology.
About the inflammation in sarcoidosis, eMedicine states: "Studies have shown an increase in B-cell activity with hypergammaglobulinemia noted in about one half of patients and in nonspecific immune-complex formation," and "Immune dysregulation has been theorized to be due to a persistent antigen of low virulence that is poorly cleared by the immune system, leading to a chronic T cell of the Th1 subtype response, which results in granuloma formation."

See Also
*http://en. .org/wiki/*http://en. .org/wiki/Chronic_inflammation
*http://en. .org/wiki/Inflammation

Footnotes

Main Menu