Keeping the patches dry is the most important aspect of accurate patch testing.

Water or moisture of any description will often cause the allergens to dissolve out of their chambers and often make results difficult to interpret.

For the whole 4 to 5-day testing period whilst the patch tests and ink markings are on your skin:

Don’t:

• Get the patches or markings wet in the bath or shower
• Work up a sweat by exercising too hard
• Go swimming
• Wear pale or valuable clothing as the ink may stain it
• Expose yourself to sunlight
• Take immunosuppressive medications (If you already taking these, patch testing is not likely possible as the results will be suppressed)

If the area becomes itchy, try not to scratch.

Do:

• Use the shower cautiously and attempt to sponge wash yourself whilst keeping the patches/markings out of the water flow
• Shower on the morning before your patch test (as you won’t be able to have a proper shower for at least a further 96 hours)
• Enjoy a holiday from exercise or sport that causes you to sweat
• If you notice a patch coming away, try to tape it down yourself
• Contact the clinic if you have questions or concerns
• Remember, these restrictions and recommendations need to cover the entire period from the first visit right through to the last, or the results may be invalidated

If you have a positive allergy, the biggest side-effect people suffer with will be itching. Sometimes you can also get an irritant reaction under the tape and this is also itchy.

• Occasionally reactions can become red, swollen or even blistered
• In strong positive allergies persistent reactions may occur which take a few weeks to disappear
• Eczema may flare up in the presence of positive patch test
• Inflammation can cause pigment change which may lighten or darken and sometimes lasts for a few months but is rarely permanent

Patch testing is not advisable if you:
• are pregnant or breastfeeding
• have extensive eczema on your back
• have been exposed to the sun or have used a sun bed over the previous 2 weeks
• have recently applied an artificial tan
• are using moderate or high dose oral steroids

It is not possible to apply test patches if the skin on your back is scratched, sun burnt, has a rash or excessive hair growth. If you do have excessive hair on your back, please have the area shaved before your appointment.

Avoid using antihistamines for 48 hours before and during the patch testing period as this would reduce any visible reaction to the allergens.