Allergist

Patch Testing

Allergy testing used to identify delayed skin reactions to contact allergens.

What is Patch Testing?

Patch testing is a method used to identify substances that may be causing delayed allergic skin reactions, such as contact dermatitis. Small amounts of suspected allergens are placed on the skin, usually on the back, and checked over several days.

This procedure helps to:

Identify causes of allergic contact dermatitis
Evaluate skin reactions to products or materials
Support diagnosis of delayed allergic skin responses
Help patients avoid specific contact triggers
Guide long-term skin care and prevention

What to expect after Patch Testing?

Adhesive patches containing possible allergens are placed on the skin and left in position for a period of time. Follow-up visits are needed so the provider can examine the skin and determine whether a delayed reaction has occurred.

Patches are placed on the skin, often on the back
You may need to keep the area dry until follow-up
Several visits are usually needed for reading the results
Itching or irritation can happen at a positive site
Results help identify contact allergens to avoid

Why is it performed?

• To evaluate chronic or recurrent dermatitis
• To identify reactions to metals, fragrances, preservatives, or chemicals
• To investigate rashes linked to personal care or workplace products
• To guide trigger avoidance
• To support long-term skin management

Risks and Considerations

• Temporary itching or rash at the test site
• Skin irritation from the adhesive or allergen
• Need to avoid sweating or wetting the area
• Multiple visits are required
• Rarely, a stronger localized skin flare may occur

Early detection is important for managing the condition and preventing further complications.

Schedule a consultation today.

FAQs

Is patch testing painful?

It is usually not painful, though positive sites can become itchy or irritated.

How long does patch testing take?

The process takes place over several days because the skin must be checked more than once.

Can I shower with the patches on?

Your provider will usually ask you to keep the area dry and avoid activities that loosen the patches.

What kinds of allergies does patch testing check?

It checks for delayed contact allergies, not the same immediate allergies evaluated with skin prick testing.

When should I call my doctor?

Call your provider if the skin reaction becomes severe, the patches come off early, or you are unsure how to care for the test area.

Allergist

Doral Health & Wellness Allergist Department

Are allergies disrupting your life? Whether you’re dealing with seasonal discomfort, food sensitivities, or unexplained reactions, our expert allergists in Brooklyn, NY, are here to help. We specialize in identifying your triggers and crafting personalized treatment plans to bring you relief.