过敏试验-皮肤

定义

Allergy skin tests are used to find out which substances cause a person to have an 过敏反应. 这些物质被称为过敏原.

选择的名字

Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test; Allergic rhinitis - allergy testing; Asthma - allergy testing; Eczema - allergy testing; Hayfever - allergy testing; Dermatitis - allergy testing; 过敏测试; Intradermal allergy testing

如何执行测试

There are three common methods of allergy skin testing.

皮肤点刺试验包括:

• Placing a small amount of substances (过敏原) that may be causing your symptoms on the skin, 最常见于前臂, 上臂, 或回.
• The skin is then pricked so the allergen goes under the skin's surface.
• The health care provider closely watches the skin for 肿胀 以及发红或其他反应的迹象. Results are usually seen within 15 to 20 minutes.
• 几个 过敏原 可以同时检测吗. 

皮内皮肤试验包括:

• Injecting a small amount of allergen into the skin.
• The provider then watches for a reaction at the site.
• This test is more likely to be used to find out if you're allergic to bee venom or penicillin. Or it may be used if the skin prick test was negative and the provider still thinks that you're allergic to the allergen.

Patch testing is a method to diagnose the cause of skin reactions that occur after the substance touches the skin:

• Possible 过敏原 are taped to the skin for 48 hours.
• The provider will look at the area in 72 to 96 hours.

如何准备考试

Before any allergy testing, the provider will ask about:

• 疾病
• 你在哪里生活和工作
• 生活方式
• 食物和饮食习惯

Allergy medicines can change the results of skin tests. Your provider will tell you which medicines to avoid and when to stop taking them before the test.

考试的感觉如何

Skin tests may cause very mild discomfort when the skin is pricked.

你可能会有瘙痒等症状, 鼻塞, 水汪汪的红眼睛, or a skin rash if you're allergic to the substance in the test.

In rare cases, people can have a whole-body 过敏反应 (called 速发型过敏反应)，这可能会危及生命. This usually only occurs with intradermal testing. Your provider will be prepared to treat this serious response.

斑贴试验可能会刺激或发痒. These symptoms will go away when the patch tests are removed.

为什么要进行测试

Allergy tests are done to find out which substances are causing your allergy symptoms.

Your provider may order allergy skin tests if you have:

• 花粉热(过敏性鼻炎) and asthma symptoms that are not well controlled with medicine
• 荨麻疹, 血管性水肿
• 食物过敏
• 皮疹(性皮炎), in which the skin becomes red, sore, or swollen after contact with the substance
• 青霉素过敏
• 毒液过敏

Allergies to penicillin and related medicines are the only drug allergies that can be tested using skin tests. Skin tests for allergies to other drugs can be dangerous.

The skin prick test may also be used to diagnose food allergies. Intradermal tests are not used to test for food allergies because of high false-positive results and the danger of causing a severe 过敏反应.

正常的结果

A negative test result means there were no skin changes in response to the allergen. This negative reaction most often means that you are not allergic to the substance.

In rare cases, a person may have a negative allergy test and still be allergic to the substance.

异常结果意味着什么

A positive result means you reacted to a substance. Your provider will see a red, raised area called a wheal.

Often, a positive result means the symptoms you're having are due to exposure to that substance. A stronger response means you are likely more sensitive to the substance.

People can have a positive response to a substance with allergy skin testing, but not have any problems with that substance in everyday life.

皮肤测试通常是准确的. 但, 如果过敏原的剂量很大, even people who are not allergic will have a positive reaction.

Your provider will consider your symptoms and the results of your skin test to suggest lifestyle changes you can make to avoid substances that may be causing your symptoms.

参考文献

Chiriac AM, Bousquet J, demmy P. In vivo methods for the study and diagnosis of allergy. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. Middleton's Allergy: Principles and Practice. 9日艾德. Philadelphia, PA: Elsevier; 2020:chap 67.

Homburger HA, Hamilton RG. 过敏性疾病. 见:McPherson RA, Pincus MR，编辑. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23日艾德. Philadelphia, PA: Elsevier; 2017:chap 55.