How to Identify the Allergen Causing Skin Allergy
Apr 14, 2022
Source: Cainiu Health
Dr. Gan Liqiang
Introduction
How to Identify the Allergen in Skin Allergies:
1. **Skin Prick Test**: A small amount of highly purified allergen solution is placed on the patient’s forearm, and a lancet is used to lightly prick the skin surface. The skin reaction is observed after 20 minutes.
2. **Intradermal Test**: Allergen solution is injected into the dermis (skin layer), and results are assessed after 20 minutes.
3. **Patch Test**: Used to diagnose contact dermatitis, cosmetic dermatitis, and similar conditions.
When experiencing skin allergies, it is essential to identify the specific allergen(s) responsible. This allows for targeted, cause-specific treatment and optimal therapeutic outcomes. During allergen testing, physicians first conduct a diagnosis based on each patient’s individual clinical presentation and symptoms. So, how can one identify the allergen(s) triggering a skin allergy? Let’s explore the common methods below.
How to Identify Allergens in Skin Allergies
1. Skin Prick Test
To identify allergens causing skin allergies, patients should visit a hospital for a skin prick test. In this test, a small amount of highly purified allergen solution is placed on the inner forearm, followed by gentle puncturing of the skin surface using a sterile lancet—held in place for only one second before removal. After 20 minutes, the test site is examined: a positive reaction is indicated by a raised, red, itchy wheal resembling a mosquito bite, or by noticeable color change at the puncture site.
2. Intradermal Test
The intradermal test involves injecting a small quantity of allergen solution into the dermis layer of the skin. Results are assessed after 20 minutes; a positive reaction manifests as a wheal (raised, swollen area) surrounded by erythema (redness).
3. Patch Test
The patch test is primarily used to diagnose type IV hypersensitivity reactions—such as contact dermatitis or cosmetic-induced dermatitis—and offers high specificity for identifying allergens involved in delayed-type allergic responses.
4. Blood Testing
Blood tests for allergen identification are mainly employed for inhalant or food-related allergies. These assays utilize radioallergosorbent testing (RAST) or enzyme-linked immunosorbent assay (ELISA) techniques. They are particularly suitable for diagnosing allergic asthma, seasonal allergic rhinitis, and atopic dermatitis. Regardless of the testing method selected, patients must discontinue antihistamines and other anti-allergic medications for at least three days prior to testing to avoid interference with results.
The above outlines the primary approaches for identifying allergens in cases of skin allergy. For accurate and safe allergen testing, it is recommended to consult a qualified dermatologist at an accredited medical institution. We hope this information proves helpful to you.
