周皮肤荨麻疹课件.ppt

Urticaria CHEN Aijun MD Department of Dematology, The First Affiliated Hospital, Chongqing Medical University Definition These are wheals, white or red evanescent plaques generally surrounded by a red halo or flare. Fast appearing and diminishing, no trace after diminishing. Etiology Foods Medicines Infections Physical factors Animals and plants Spirit factors Diseases of internal organs Etiology 1. Foods The most allergenic foods are shellfish, shrimps, crab, chocolate, nuts, peanuts, tomatoes, strawberries, melons, pork, cheese, garlic, onions, and spices. Eggs and milk always induce urticaria in children. 2. Medicines Many medicines can start urticaria by allergy, the most common drugs are as follows: penicillin, serum, vaccine, furazolidone, sulfanilamide and so on . Sometimes a few drugs can directly stimulate mast cells to produce histamine, like aspirin, morphine, codeine, quinine, etc. 3. Infections Infections caused by all organisms are another possible reasons to induce urticaria. The most common organism is virus of upper respiratory and staphylococcus aureus. Chronic infections of the patients cannot be easy verified as the pathogen of urticaria; it must be tested by therapy. 4. Physical factors: Cold, hot, sunlight, friction and pressure 5. Animals and plants : Urticaria can be induced by animals fur skin or pollen or stinging of insects. 6. Spirit factors: In some cases, stress can trigger urticaria, but in another cases stress may lead to histamine releasing. 7. Diseases of internal organs Rheumatic disorder, rheumatoid arthritis, systemic lupus erythema, malignant tumor, disorder of endocrine and some others can be another reasons of urticaria. Pathogenesis 1. Allergy anaphylactic type immune complex type and allergic vasculitis The wheal results from increased capillary permeability, which allows proteins and fluids to extravasate. Capillary permeability results from the increased release of hist