2.2 Application and evaluation of skin prick test
Skin prick tests were applied on the anterior surface of the forearm
when they were appropriate for test such as they were not taking
antihistamines. Histamine (10 mg/ml) and physiological saline were used
as positive and negative references, respectively. Skin reactions were
evaluated 20 min after the application of the skin test, and indurations
of 3 mm was considered indicative of a positive reaction. Skin prick
tests Skin prick tests including: Dermatophagoides pteronyssinus,
Dermatophagoides farinea, artemisia powder,phoenix tree pollen, birch
pollen, cockroach, mold, shrimp, cat and dog dander (Peking Union
Medical College Hospital, Peking, China). A positive reaction was
characterized as 3 mm or greater than that of the negative control. Skin
prick test for the same allergens was performed for all patients.