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A bronchial challenge test is a medical test used to assist in the diagnosis of asthma. [1] The patient breathes in nebulized methacholine or histamine. Thus the test may also be called a methacholine challenge test or histamine challenge test respectively. Both drugs provoke bronchoconstriction, or narrowing of the airways.
Commercial laboratories provide a 24-hour urine sample test for 1,4-methyl-imidazolacetic acid, the metabolite of histamine. This test is a valuable tool in assessing the metabolism of histamine in the body, as direct measurement of histamine in the serum has low diagnostic value due to the specificities of histamine metabolism. [48] [49] [50]
Histamine intolerance is a presumed set of adverse reactions (such as flush, itching, rhinitis, etc.) to ingested histamine in food. The mainstream theory accepts that there may exist adverse reactions to ingested histamine, but does not recognize histamine intolerance as a separate medical condition that can be diagnosed. [1]
Diagnosis of allergy is most often done by reviewing a person's medical history and finding a positive result for the presence of allergen specific IgE when conducting a skin or blood test. [33] Specific IgE testing is the proven test for allergy detection; evidence does not show that indiscriminate IgE testing or testing for immunoglobulin G ...
A test tube is prepared with basophil stimulation buffer (BSB) including Interleukin 3 and an allergen which is to be tested. The blood sample is added and the tube is incubated at 37 °C for several minutes, to ensure that the allergens can bind to the IgE. By adding EDTA to the test tube, the degranulation process is stopped immediately ...
Degranulation in mast cells is part of an inflammatory response, and substances such as histamine are released. Granules from mast cells mediate processes such as "vasodilation, vascular homeostasis, innate and adaptive immune responses, angiogenesis, and venom detoxification."
A person receiving a skin allergy test. A microscopic amount of an allergen is introduced to a patient's skin by various means: [1] Skin prick test: pricking the skin with a needle or pin containing a small amount of the allergen. [2] Skin scratch test: a deep dermic scratch is performed with help of the blunt bottom of a lancet. [3]
Histidine decarboxylase is the primary biological source of histamine. Histamine is an important biogenic amine that moderates numerous physiologic processes. There are four different histamine receptors, H 1, H 2, H 3, and H 4, [16] each of which carries a different biological significance.