What’s a Contact Patch Test?
Contact Patch Testing is used for the diagnosis of Allergic Contact Dermatitis.
Who is suitable for a Contact Patch test?
Contact patch testing can be conducted for children above 2 years old and adults.
It can help identify the cause of an Allergic Contact Dermatitis when the cause is unclear.
What Do Contact Patches specifically tests for?
The patch tests we use screen for the most common causative agents of contact dermatitis. Substances tested include:
- Allergen components commonly found within jewellery, metal, cosmetics, skin care products, soaps, fragrances, hair shampoos, conditioners and dyes, topical medications, creams and ointments , adhesives and bandages, fabrics, inks, household disinfectants and industrial products, everyday materials
Can I develop a contact allergy years after using something?
Yes, it is possible to become allergic over time.
Can a Contact patch test tell me if I have Nickel or Cobalt or metal allergy prior to Joint replacement?
Although serious reactions to metal implants are rare, if you have ever had reaction to metal such as costume jewellery your orthopaedic surgeon may recommend a contact patch test prior to ensure you don’t have a metal allergy.
Who should consider a contact patch test?
- Occupational rashes
- Anatomically localised skin rashes such as face, eyelids or hands
- Hand dermatitis
- Uncontrolled dermatitis
Which Contact Patch test do you use?
We use Chemotechnique diagnostics which and test from the ABS-60 which is Australia’s most common allergens causing Allergic Contact Dermatitis.
How do I prepare for a Contact patch test?
The administration of oral corticosteroids, and application of topical corticosteroids to the test area (upper back), must be ceased two weeks prior to patch testing, and continue to be avoided for the duration of the patch test and review period. This is important as such pharmacological treatments may suppress or alter a positive reaction and interfere with accurate test interpretation
Should patients be tested for metal allergies before joint replacement?
Routine allergy testing in individuals with no symptoms is not indicated prior to joint replacement surgery.
However, if there is a history of suspected metal allergy such as reacting to nickel in costume jewellery or watches, then patch testing is the best screening tool.
For those who are concerned about an existing joint replacement, post-implantation testing is controversial and patch test does not definitively diagnose morbidity from a metal allergy.
How do you do perform the test?
Patches are typically placed on an individual’s back and worn for 48 hours. The test area is then examined for signs of an allergic reaction at 48 and 72-96 hours following initial patch application.