We offer a patch and prick testing service at Chapel Allerton Hospital which is led by Dr Mark Wilkinson. Patch testing is a test that can help your doctor determine whether your skin condition is caused by an allergy to substances in contact with your skin e.g. substances at home or at work.
If you think that you have an allergy as a cause of your skin condition, you will need to visit your GP who will refer you to the department.
If you already have patch test appointments at Leeds General Infirmary arranged, please read through the information below.
To what will I be tested?
You will be tested with approximately 40 standard substances commonly in contact with the skin e.g. rubber chemicals, metals, perfumes and plants. You may also be tested on additional substances, dependant on your skin problem. This may also include some of your own work or home products.
What should I bring to the Patch Test clinic?
- For your first appointment, please bring the following with you.
- A list of medication & prescribed drugs that you are taking.
- All ointments and creams that you use, including over the counter creams.
- our own products from home that you think you might be allergic to e.g. toiletries, cosmetics, nail polish, perfumes and hair care products. Please bring the product packaging with you that will list all the contents.
- If you think you are allergic to any work chemicals that may be aggravating or causing your rash, you will need to deliver the substance samples two weeks before your appointment. The samples need to be in well sealed labelled containers and need to be delivered to the following address.
Dr Mark Wilkinson, Dermatology Outpatients, First Floor, Chapel Allerton Hospital, LS7 4SA.
When delivering your samples you also need to provide the Health and Safety data sheets which will be available at your place of work.
What does Patch Testing involve?
Three visits to the hospital are required in one week. At the first appointment (Monday morning) you will be interviewed by the Dermatologist who will decide what tests are needed. The substances which need to be tested will be applied in special small containers to your back, and the sites will be marked with ink. If your back is hairy, we may need to shave your skin first. You will need to allow 2 hours for this visit.
The samples will be taped to your back and will remain in place until your second visit on Wednesday morning. The substances will be removed from your back and any reactions will be noted. Additional patches may be applied at this stage. Please allow 30 minutes for this appointment.
At the third visit (Friday morning) you will be examined by a doctor who will discuss any reactions with you. The sites on your back may itch but this is completely normal. At this visit it may be necessary to expose part of your back to ultraviolet light if we suspect a light induced contact allergy. This is known as Photopatch Testing. A standard Friday appointment should only take 30 minutes, but this will take longer if you need Photopatch Testing.
It is possible that your Patch Tests will be negative. This is helpful because we will have eliminated contact allergy as the cause of your skin problem. Positive reactions become red and itchy at the test site and this usually happens in time for the Friday appointment. However, it may be possible for your skin to develop a late reaction. If this happens please ring Dr Wilkinson's secretary on 0113 3924357. Sometimes the substances may stain the skin or clothing, but this is normal.
We may not Patch Test you if you are pregnant, breast feeding, have extensive eczema on your back, have had sun exposure or used a sun bed over the previous 2 weeks, or are on a moderate to high dose of steroids. If any of these apply to you, please phone the Referral and Booking service to rearrange your appointment - 0113 2064819.
During your Patch Testing treatment
- DO NOT get your back wet during the tests. You can wash down with a flannel.
- DO NOT wear your best clothes as the marker ink may stain.
- DO NOT expose your back to the sun during this procedure.
- DO avoid sport or heavy physical work during the week of the tests.
- DO wear an old bra or t-shirt for the week of the tests. Also wear a t-shirt or vest to sleep on to protect the tests.
- If a patch test peels off, reinforce using tape. If a whole patch comes loose, remove it and note the time & date.
Do contact us if you have any concerns. Please ring Dr Wilkinson's secretary on 0113 3923661.
What side effects may occur?
Side effects are rare but may include:
- Skin reddening and itching from positive test results. This usually disappears after a few days.
- Persistent reaction to some positive test reactions e.g. A reaction to gold may persist for up to one month.
- Flare of eczema. A positive Patch Test may be accompanied by a flare of existing or previous eczema.
- Pigmentary change. An increase or decrease in pigment may be seen at the site of the Patch Tests.
- Infection or scarring, but both of these are rare.
- Allergy. Very rarely (approx 1 in 500 times) you may become allergic to one of the substances applied during Patch Testing. In practice this does not seem to cause a problem in the long term.
Storage of test results
We will record the information about your Patch Test results in an anonymised form on a computerised database. We will use the results for audits, in accordance with good medical practice. The date may be used for research and may be shared with other centres.
Failure to attend
Failure to attend your Patch Test appointments without informing us, will result in you being discharged and referred back to your GP.
You can also visit the British Society For Cutaneous Allergy website where you can download patient leaflets for each allergy. The patient leaflets offer lots of useful information, including things to avoid for each allergy.