Urticaria is commonly known as rubella. It is a limited edematous reaction due to dilatation of small blood vessels in the skin and mucous membranes and increased permeability, which usually subsides within 2 to 24 hours, but new rashes occur repeatedly. The course of the disease is prolonged for several days to several months. It is more common in clinical practice. So what are the examination items for urticaria? 1, suspected of rheumatism caused by urticaria can check the blood sedimentation, anti-nuclear antibodies, serum complement determination, skin biopsy for the diagnosis of urticaria caused by the involvement of complement activation is helpful. 2, for cold urticaria should be checked for syphilis serum test, determination of cold globulin, cold fibrinogen, cold hemolysin and ice test, anti-nuclear antibodies and other tests. 3.Solar urticaria should be examined for fecal and urinary porphyrins, etc. Attention should be paid to differentiate it from SLE. 4.Suspected to be related to infection, or physical examination with large liver or history of hepatitis, routine blood, hepatitis B antigen, antibody test, stool worm eggs, fungus, X-ray of the lesion site, etc. are feasible. 5. If thyroid disease is suspected, anti-microsomal thyroid antibody-related tests should be performed. 6.If inhalation or ingestion allergy is suspected, an allergen test should be performed, and if positive, desensitization treatment can be performed. 7.Patients with serous urticaria with fever and arthralgia should have their blood sedimentation checked, and if the blood sedimentation is normal, it has important diagnostic value. 8, urticarial vasculitis attack in addition to obvious hypocomplementemia, serum Cl subunit Cla significantly reduced, C4, C2 and Cg moderate to severe reduction, the serum appear circulating immune complexes and low molecular weight Clq precipitin, direct immunofluorescence examination can be seen in the skin vascular wall with immunoglobulin and complement deposition. 9, autoimmune chronic urticaria can be detected autoantibodies, using their own serum skin test: routine blood sampling into sterile test tube clotting 30min, centrifugation, take 100μl of serum to the patient for intradermal test, saline as a control, such as 1h after the local appearance of wind mass diameter greater than 9mm is positive, other such as histamine release test, immunoblotting method and enzyme-linked immunosorbent assay can be used.