Chemical Allergy

TRUE Test

TRUE Test® (Thin-layer Rapid Use Epicutaneous Test) is a ready-to-use patch test system for diagnosis of allergic contact dermatitis.

The TRUE Test® system consists of surgical tape/plaster containing allergens or allergen mixes – all well-known causes of contact dermatitis.

Patient information leaflet/pack insert

The TRUE Test® system consists of 3 pieces of surgical tape/plaster (panels) containing 29 (or more) allergens or allergen mixes – all well-known causes of contact dermatitis. We have recently launched panel 3 with 5 new allergens so we now have 34 allergens allergens available – contact your local distributor for more information.

The test is developed to determine whether or not you are allergic to any of the substances included on the test panel.

The concentration of each allergen has been established so that it is high enough to evoke a reactioneven in weakly sensitised patíents – yet low enough to minimise the risk of irritant reaction.

Table inserted here

What is TRUE Test® ?
TRUE Test® (Thin-layer Rapid Use Epicutaneous Test) is a ready-to-use patch test system for diagnosis of allergic contact dermatitis. Allergic contact dermatitis is an inflammatory reaction that occurs when substances to which you are allergic come in contact with your skin. These substances could be an ingredient in your perfume or aftershave, an antibiotic ointment or cream, rubber boots etc.

Manufacturer
SmartPractice Denmark ApS (former MEKOS Laboratories ApS)
Herredsvejen 2
3400 Hillerød Denmark

Distributor
Click here for distributor list

Are there any special instructions that I must follow while using TRUE Test® ?
TRUE Test® can be used all year. Moisture around the test area must be avoided. Therefore, when bathing or showering, you must be careful not to get the test panel or surrounding area wet. If the test panel does become wet, it may loosen and the test must be repeated. For the same reason, any activity such as sunbathing or exercising, which may cause you to sweat, should be avoided.

What other precautions or warnings should I be aware of before using TRUE Test® ?
The substance on the test panel seldom lead to sensitisation. A test reaction that appears later than 10 days after application of the test may be a sign of contact sensitisation. Excited skin syndrome (angry back) is a state of hyperreactivity induced by dermatitis on other parts of the body or by a strong positive skin test reaction. Therefore, test results should be evaluated carefully in patients with multiple, positive, concomitant patch test results. To determine which reactions are false positive, retesting at a later date may be necessary.

The doctor should avoid applying the test on skin with acne, scars, dermatitis or any other condition that may interfere with test results.

If a severe patch test reaction develops, the patient may be treated with a topical corticosteroid or, in rare cases, with a systemic corticosteroid.

Pregnancy and lactation
TRUE Test® is not recommended to be applied to the skin of pregnant or breastfeeding women. Children: TRUE Test® is not recommended for use in children. Precautions by use together with other medicaments and other forms of interaction Since steroids may supress a positive test reaction, use of topical steroids on the test site or oral steroids (equivalent to 10 mg prednisolone) should be discontinued for at least two weeks prior to testing.

An identification template is provided with each package of TRUE Test®. Notice the difference between page 1 and 2 on the template corresponding to panel 1 and 2.

The patient must wear TRUE Test® for a minimum of 48 hours without removing it and being careful not to get the test area wet (water, sweat). Following this period, the test is removed either by the physician or the patient.

When should the results be read ?
The reaction should be read 1/2 a hour after removal of the test and again 1-2 days after removal, when the allergic reactions are fully developed and mild irritant reactions have faded.

Neomycin sulphate and p-phenylenediamine, however sometimes cause reactions, which may not appear until 4-5 days after the application. Patients should be instructed to report this. If appropriate, an additional office visit will verify a late reaction.

What is the doctor looking for ?
The doctor will carefully examine the test area for signs of an allergic reaction. This reaction usually consists of rash with swelling, redness and tiny blisters. Redness alone, however, does not necessarily mean that it is an allergic reaction. If you are allergic, the doctor will provide information on where in the everyday surroundings you are likely to come in contact with the offending substances. The doctor will also tell how best to avoid these substances and often suggest alternatives to the items that should be avoided.

Information to the doctor
An identification template is provided with each package of TRUE Test® for quick identification of any allergen, which causes a reaction. To assure correct positioning, marks on the skin should correlate with the notches on the template. Notice the difference between page 1 and 2 on the template corresponding to panel 1 and 2.

The interpretation method recommended by the International Contact Dermatitis Research Group is:

? doubtful reaction; faint macular erythema only
+ weak (nonvesicular) positive reaction; erythema, infiltration, possible papules
++ strong (vesicular) positive reaction; erythema, infiltration, papules, vesicles
+++ extreme reaction
– negative reaction IR irritant reaction of different types NT not tested

Note
Patients showing a negative reaction may still be sensitised to another substance not included in this test panel. Furthermore, false-negative results may occur. Retesting or testing with complementary substances may be indicated.

A positive reaction should meet the criteria for an allergic reaction (papular or vesicular erythema and infiltration).

Pustules, as well as patchy follicular or homogeneous erythema without infiltration are usually signs of irritation and do not indicate allergy.

What is important in evaluation a positive test response is not the number of plusses assigned to the test response, but determining whether the response is a truly positive reaction (caused by allergy) or a non-specific irritant reaction.

Overdose
Not relevant

What are the possible undesirable effects of TRUE Test® ?
A flare-up of your dermatitis if the test is used during an active phase of your condition. A positive test reaction usually disappears within 1-2 weeks. On rare occasions, test reactions may persist for a month, leaving an area of transient hypopigmentation. Irritation caused by the surgical tape adhesive may occur, but usually disappears rapidly.

How should TRUE Test® be stored ?
Storage at 2-8 °C. Expiry date is stated on the package must not be exceeded.

Published with permission from http://mekos.dk