Causes of hives

 Urticaria is commonly referred to as “rubella”. It is a limited edematous reaction due to dilatation of small blood vessels in the skin and mucous membranes and increased permeability, and usually resolves within 2 to 24 hours, but new rashes occur repeatedly and last for days to months.  
  Etiology
  The cause of urticaria is complex and cannot be found in about 3/4 of patients, especially in chronic urticaria
  1.Food and food additives
  Such as fish, shrimp, crab, meat, eggs and other animal protein food; eggplant, bamboo shoots, spinach, apples and other vegetables and fruits; preservatives, flavorings, food coloring and other food additives.
  2.Inhalation
  Such as pollen, animal dander, feathers, fungal spores, dust, formaldehyde, pesticides, etc.
  3.Infection
  Such as acute tonsillitis, pharyngitis, impetigo, boils de and other bacterial infections; viral infections such as viral hepatitis; parasites, etc.
  4.Drugs
  Common drugs such as penicillin, sulfonamide, serum, vaccines, aspirin, morphine, etc.
  5.Physical factors
  Such as mechanical stimulation, heat and cold, sunlight, etc.
  6.Insect bites
  Bee and wasp bites, caterpillars, beetles, bag spiders and moths and other hairy scales stinging into the skin can cause.
  7, mental factors and endocrine changes
  Mental tension, emotional impulsiveness, menstruation, menopause, pregnancy, etc.
  8.Medical diseases
  Systemic lupus erythematosus, lymphoma, carcinoma, hyperthyroidism, rheumatoid disease, rheumatoid arthritis, hyperlipidemia and chronic lesions.
  9.Hereditary factors
  Family history
  Tips
  Allergen testing
  In the case that patients cannot analyze what they are allergic to on their own, they can consider using allergen testing for examination, and the results are available for reference. The results can be used as a reference. The allergy has to be further confirmed by the experience in daily life.