Pediatric urticaria is caused by infection, allergy and other factors, and laboratory tests for blood tests and inflammatory indicators are necessary. If the total white blood cell count and neutrophil fraction are elevated, it is usually due to bacterial infection, which may be caused by pharyngitis or tonsillitis, etc. In this case, oral cefaclor granules or azithromycin dry suspension are needed for anti-inflammatory treatment. If the total white blood cell count decreases and the lymphocyte fraction increases, it may be caused by a viral infection and can be treated with oral Pancreatin granules. In addition, if the blood eosinophil fraction is elevated, it means that the allergy is obvious and can be treated with oral dexloratadine dry suspension.