Testing with non-standard allergens prior to eye surgery

Question:

An ophthalmologist is planning a cataract surgery for a patient who recently developed a severe allergy to vinyl and ether. He wants to know he can put an "acrylic" lens in the patient's eye. Is there any way to do this? The material is proprietory.

Answer:

Exposure to acrylic materials can produce contact dermatitis, and the acrylics were named the contact dermatitis agent of the year for 2012.

Several diagnostic methods can be used in this case and the patch test for contact dermatitis is a step in the right direction.

There are two basic types of patch tests:

- a commercial test with ready-made ingredients, such as the the T.R.U.E. test http://www.truetest.com/panelallergens.aspx

- a test with Finn chambers using non-standard allergens

There are several tests that can be used to evaluate a patient with contact urticaria.

For immunologic urticaria, you can certainly use the standard allergy prick test, but for non-immunologic urticaria, the prick test would not be applicable.

Suggested tests:

1. A “use test” is for both immunologic and non-immunologic contact urticaria. This is done by applying the suspected substance by the patients as they would in their every day routine, and observing the reaction.

2. An “open test” consists of applying the substance over a 3 x 3 cm. area of the skin and the reaction is observed over an hour.

3. A contact patch test is applied for 15 to 20 minutes (up to an hour), and then removed.

4. The Finn chamber can be used. Appropriate controls should be used with these tests.

Here is a simple protocol for latex testing:

1. Ask the patient to bring in the gloves in question and soak them in saline for an hour; then prick the skin using the solution from the soak, and read the results as you would any standard prick test.

2. If this test is negative, place a wet glove on the forearm and prick through the glove

3. If that test is negative, perform a modified "use test" by letting the patient wear a glove on the hand for a maximum of one hour (removing the glove if the patient develops symptoms).

4. The same type of test can be repeated with the other suspected substances. Do not pressure on the skin so that you rule out pressure urticaria. Use appropriate controls.

A 48-hour patch test with the standard agents may be of less value in this case.

References:

Contact urticaria to multiple substances. Ask the Expert, AAAAI.
Possible allergic reaction to acrylic intraocular lens. Ask the Expert, AAAAI.

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