Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042109 (urticaria)
 6,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The porphyrias can be grouped conveniently by their presenting symptoms. Acute intermittent neurological symptoms of neuritis, abdominal pain and psychoses may occur in acute intermittent porphyria, hereditary coproporphyria and variegata porphyria. Increase of the porphyrin precursors delta-aminolaevulinic acid and porphobilinogen may be observed in the urine during attacks (Watson-Schwartz test). Patients with acute symptoms of photosensitivity with burning pain and oedema within short exposure periods may have erythropoietic protoporphyria, with high erythrocyte and stool protoporphyrins, erythropoietic coproporphyria, and in the last few years of life the more recently described hepatoerythropoietic porphyria. Symptoms of chronic photosensitivity include; hyperpigmentation, hypertrichosis, easy fragility of the skin with bullae and subsequent scarring in porphyria cutanea tarda (PCT), with increased uroporphyrin in the urine and stool; variegate porphyria with increased protoporphyrin and coproporphyrin in the stool; congenital erythropoietic porphyria with an increased copro- and uroporphyrin (isomer I) in the erythrocytes, urine and stool; and hepatoerythropoietic porphyria in later life, in which the chronic features are similar to PCT. In 1913 Meyer-Betz injected himself with 200 mg haematoporphyrin. Initially, at the higher levels, the symptoms were those of solar urticaria as observed in erythropoietic porphyria, but after several months became identical to PCT. A comparison of quantitative porphyrin analysis (performed on 323 patients with porphyria) and chromatography provides additional confirmation for the diagnosis.
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PMID:Porphyria: genetic and acquired. 329 37

The general features of allergic drug reactions in man have recently been reviewed by Parker (85). By definition allergic drug reactions are produced by specific immunologic processes. Allergic drug reactions must be distinguished from adverse reactions due to overdosage, normal pharmacologic action, toxic metabolite formation, idiosyncrasy, nonspecific release of pharmacologic effector molecules, or drug interactions. The clinical manifestations of drug allergy are quite protean. In addition to classical manifestations of allergy such as serum sickness, anaphylaxis, contact dermatitis or urticaria, drug allergy may produce hemolytic anemia, thrombocytopenia, granulocytopenia, hepatitis, nephritis, pneumonitis, vasculitis, or neuritis where a single organ or cell type is affected. While many drugs produce reactions with suggestive of allergy, definitive experimental evidence either for or against mechanism is usually not available. Some of these reactions may involve allergic mediators released or produced nonimmunologically through pharmacologic, osmotic, or toxic effects on cells involved in immune inflammation (mast cells, basophils, phagocytes, and lymphocytes) or through nonspecific activation of effector molecules in extracellular fluid such as the complement proteins. Drugs may also induce the formation of autoantibodies through mechanisms that are largely obscure, but may in some instances involve the direct participation of the drug as a hapten and in other instances occur indirectly through a pharmacologic or toxic action on the cells responsible for immune homeostasis.
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PMID:Allergic reactions in man. 704 Nov 44