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Patch Testing


Patch Testing for Allergies Questions and Answers

If you have skin sensitivities or break out in rashes, Allergy and Asthma Clinic of Maryland provides patch testing to help determine what your skin is allergic to. For more information, please call us or book an appointment online. We serve patients from Silver Spring MD, Ammendale MD, Takoma Park MD, College Park MD, Langley Park MD, and Rockville MD.

Patch testing helps to diagnose the causes of contact dermatitis early and treat the problem before it becomes chronic, thereby reducing resources used and considerably bettering patient quality of life. Patch testing has improved the lives of millions of people with its effective ability to diagnose allergies.

What is an allergy patch test?

A patch test is an allergy test that can identify delayed allergic reactions that can appear after several days. Patch tests are non-invasive in that they don’t use needles. Instead, up to 30 extracts of allergens are applied to patches, which are then placed on your skin (usually on your back or arm). Reactions are observed over several days.

What are some allergens that are used in a patch test?

The most common chemical allergens tested in a patch test are nickel, formaldehyde, leather, fragrance, toiletries, hair dyes, rubber, lanolin, resin & food additives.

Does patch testing test for food allergies?

In addition to chemical allergy patch tests, patch testing for food allergies is common as well. This is not as invasive as allergy pricks. If there is an allergic reaction, it may take some days to show up.

Are there side effects of patch tests?

Although they are well tolerated by most patients, the most common side effect is redness or irritation due mostly to the tape. This generally disappears after the patch is removed.

Although an allergy skin test is generally considered safe, it does have some risk of side effects or complications: These include hives or wheals (swollen, red, itchy bumps on the skin).

Known as anaphylactic reactions, some people have extremely serious allergic reactions. If a person has had a previous anaphylactic reaction to an allergen, they may not have an allergy skin test for this substance as the test might provoke a hazardous reaction.

The most serious risk of having a skin prick test is anaphylactic reaction. This reaction is a medical emergency, causing difficulty breathing and a dangerously low blood pressure. However, anaphylactic reactions with skin prick tests are rare and the allergist will be monitoring you closely.

Skin testing may not be performed if you have certain skin conditions, such as atopic dermatitis or severe eczema.

Speak to your doctor if you are concerned about any symptoms following this test. Take the time to be sure you understand all of the side effects, risks and complications, as well as any precautions you or your doctor can take to avoid them. Be sure your doctor understands all your concerns.

Does allergy patch testing hurt?

The patch test method is somewhat simple and painless. In order to identify specific reactions, your physician will tape several patches that contain various potentially reactive chemicals or allergens to the skin on the back. These chemicals are then left on the skin for at least 48 hours, and must stay dry.

To get accurate results, it is better to not have a shower or perform physical activities where sweating may hinder results.

If you or someone you know is experiencing signs or symptoms of an allergic reaction, come to Allergy and Asthma Clinic of Maryland today! Our team of expert allergists can help you diagnose, treat and prevent allergies and help you live a better quality of life! To get in touch with an expert, contact our office today. To schedule an appointment with one of our specialists, call us or visit us online!


Allergy & Asthma Clinic of Maryland
8630 Fenton Street, Suite 522
Silver Spring, MD 20910
Phone: 240-332-8010
Fax: 240-847-7061

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