Histamine
A substance that plays a major role in many allergic reactions, dilating blood vessels and making the vessel walls abnormally permeable. Histamine is part of the body’s natural allergic response to substances such as pollens. Antihistamines work by preventing the release of histamine from certain cells (mast cells) thereby blocking the allergic reaction.
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- Histamine cephalalgia
a year). The other main pattern of cluster headache is termed “chronic” (and is also known as chronic migrainous neuralgia). It may come out of the blue or emerge several years after an episodic pattern. It is characterized by the absence of sustained periods of remission. The episodic and acute forms of cluster headache may […]
- Histiocyte
A type of white blood cell, also called a macrophage, that is created by the bone marrow. They usually stay in place, but when histiocytes are stimulated by infection or inflammation they become active, attacking bacteria and other foreign matter in the body. See also histiocytosis.
- Histiocytic necrotizing lymphadenitis
A disorder, also called Kikuchi disease, that typically causes “swollen glands” in the neck (cervical lymphadeniopathy) together with fever or flu-like symptoms. Laboratory test abnormalities include elevated erythrocyte sedimentation rate (ESR), and white blood count abnormalities (low neutrophil count and elevated lymphocyte count with atypical lymphocytes in the peripheral blood). Kikuchi disease rare. Also called […]
- Histiocytosis
One of several disorders in which histiocytes start to multiply and proliferate abnormally. The result can be tissue damage, pain, the development of tumor-like lumps, fatigue, and other symptoms. If histiocytosis affects the pituitary gland, diabetes insipidus may also develop. Treatment includes radiation and chemotherapy, although for reasons unknown, some cases of histiocytosis go into […]
- Histiocytosis X
Now called Langerhans cell histiocytosis. This disease is subclassified into eosinophilic granuloma, Letterer Siwe disease, and Hand-Schuller-Christian disease.