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Patch Testing

What is a Patch Test?

A patch test is a procedure used by dermatologists and other specialists to identify whether a particular ingredient might be irritating or cause an allergic reaction by testing them on the skin. Many kinds of products contain ingredients that, if left in direct contact with the skin for a prolonged period, could potentially cause people to develop ailments like itching, rashes etc.

Uses of Patch Test

Patch testing can be helpful to determine if you are allergic to certain substances by detecting delayed allergic responses. At Frontier Allergy Asthma and Immunology, our allergy specialist has extensive training and experience performing patch tests on patients who may be suffering from allergies to a variety of potential triggers.

Patch testing is a form of allergy testing that detects delayed allergic responses that present on the skin in the forms of eczema (atopic dermatitis) or allergic skin irritation (contact dermatitis). Patch testing can be a helpful method for patients who have difficulty determining the cause of a reaction that may arise days after initial exposure to an unknown allergen. Common allergens that are diagnosed using patch testing include:

  • Detergents
  • Soaps
  • Fragrances
  • Makeup
  • Hair dyes
  • Metals
  • Leathers
  • Latex
  • Medicines
  • Preservatives
  • Dental products
  • Foods

How is a Patch Test Performed

Prior to your patch test, your allergist will ask that you hold all antihistamine-related medications and supplements for at least 4 days, as even traces of these medications in the body can interfere with test results. In addition, throughout the patch testing procedure, you will be asked to continue avoiding the use of these medications.

During your patch test, your allergist will place small amounts of various suspected allergens into chambers that are secured to the back using tape. These allergens will be in contact with the skin on your back for 48-72 hours, so it is important that the area is not tampered with or exposed to water or sweat. During the 48-72 hours, it is also important not to bend or stretch too much, as the patches may shift on your back, which can interfere with test results.

After 48-72 hours of wear, you will return to your allergist’s office for patch removal and skin examination. The presence of redness or irritation in areas where certain allergens were in contact with the skin can indicate a contact allergy. Depending on the initial results of this test, subsequent skin evaluations may be necessary. Your doctor will let you know if such evaluations will be required.

Diagnosing Allergic Contact Dermatitis

Allergy patch tests are a standard medical procedure used to diagnose the underlying causes of contact dermatitis, a condition that causes inflammation and itchiness of the skin. People with contact dermatitis will get inflamed patches on their skin after contact with some allergen onto it.

The affected area may also become itchy or produce rashes as well, and as anybody who has had contact dermatitis before knows, these symptoms can spread to other areas of the body quite easily––which is why people with this allergy may have trouble controlling itching throughout their whole bodies!

Next steps

At Frontier Allergist, our consultants are certified by the American Board of Allergy and Immunology (ABAI). They will work with you to identify possible allergens and develop an allergy treatment plan. We provide patch tests for allergy sufferers, which help identify offending allergens.

If you are interested in further discussion about your specific needs, Dr. Reshamwala is happy to see you and answer any questions you may have. Please call (512) 535-2655 or email to schedule an appointment today! Book an appointment

Written by: Dr. Neha Reshamwala
NPI number: 1780874578
Page last reviewed: 03/20/21

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