Patch Tests: Should You Get One If You Have Eczema?


Sometimes, eczema can seem like a never-ending battle. 

The itch, scratch, stress, flare up cycle is one that can get stuck on repeat and seem impossible to break free from. 

Inevitably it leads every sufferer on the long and winding path to identify their ‘trigger’ and the root cause of their flare ups. 

Oh what a wonderful place the world would be if this magical, impossible to quantify enigma would just reveal itself! But, alas, it doesn’t. 

Is it dust? Dog hair? Gluten? Dairy? The weather? Stress? Shampoo? Detergent? Perfume? Disinfectant?  

Unfortunately as we know, I could go on indefinitely here. So what’s the answer? 

Whilst there’s no one size fits all solution, a patch test might be a good step in the right direction in trying to nail down that ever elusive (and ever so important) ‘trigger’. 

But remember! 

A patch test is only specific to contact dermatitis as different substances are placed onto your skin to test for a reaction. What it doesn’t analyse for is the whole host of other reasons (like stress or the weather) that might be causing your eczema to flare up. 

In this article, you’ll find: 

1) What is a patch test?

2) What does it involve and what substances will be tested for?

3) What a positive result looks like

4) Potential side effects

5) Top tips

What is a patch test? 

A patch test is a specialised proce-dure that examines whether or not your current skin condition is made worse when exposed to certain allergens

This can help you find out whether or not there is a specific substance in your work, home or leisure environment that is causing your skin to react and break out in nasty eczema patches. 

What does patch testing involve and what substances will be tested for? 

Your dermatologist will require you to go to the hospital 3 times over a 1 week period with 48 hours between each visit. 

On your first appointment the doctor will ask questions to understand your needs and then tape a number of different substances housed in small 1cm containers to your back (sometimes the arms and thighs are also used). 

It’s a damn sexy look we promise! 

On the second visit the doctor will observe your skin and remove the containers - they may even ask you to remove the tape yourself a few hours before the appointment or tape further substances on to test for. 

And then finally on the 3rd visit the dermatologist will discuss any reactions your skin has had and hopefully give you a clear path on what substances to avoid in future (we say ‘hopefully’ - sometimes it’s not always that certain). 

BE AWARE - itching of the test areas is completely normal and to be expected. 

Of course the doctors tell you not to scratch (it’s that simple, right?) but it’s important in this instance not to apply any cream to the area. 

You want the dermatologist to get an honest and true reflection of what reaction your skin has had to the allergens. 

When it comes to what substances will be tested for, clearly there are 1000s of potentials on the list which might cause an adverse reaction with your skin. 

But to narrow it down, roughly 40 are usually taken from the following groups: 

- Metals

- Perfumes

- Cosmetics

- Plants

- Chemicals

- Preservatives 

It’s also common to be tested with items that you come into contact with regularly in your work or home life. 

So be prepared to fess up to those 20 cosmetic products you’ve decided are a ‘must have’ for your night time routine! 

What does a ‘positive’ result look like? 

A positive result will involve the skin where a substance was placed becoming itchy, red or inflamed. 

If you have a particularly strong reaction a blister can sometimes form, so be aware and have someone check your back throughout the week you’re being tested. 

Are there any side effects? 

Long term, damaging side effects are very rare but there are a few instances to watch out for: 

1) Persistent reaction/continued flare up - after you’ve finished the test there’s a chance your skin may continue to flare up even after the allergens have been removed. (Did we mention we have a product to help with that?)

2) Pigment change - the colour of your skin in the test area may be altered, although this usually fades in the span of a few weeks to months.

3) Allergy - this is super rare, but you may form an allergy to one of the substances placed onto your skin (we know - that’s exactly the thing you went to try and avoid). If this is the case, it’s just one more thing unfortunately to avoid...forever...

Tips if you decide to have a patch test

1) This isn’t the time for that cute dress you just bought from ASOS. Old clothes that have been around the block a few times are on the agenda here. Why? The marker ink might stain your clothing. You’ve been warned!

2) Stock up on deodorant before you take the plunge because, you guessed it, showering is a no go the week of the test. Try a shallow bath instead and if you still feel grimey, wet wipes to the rescue!

3) Make sure you don’t expose your back to the sun or any artificial sunlight.

4) Sit back and stick your feet up - sweating is off the menu too (see it’s not all bad)

5) If a patch starts to peel off between your hospital visits, use the tape the dermatologist gives you to re-tape down the edges. If the container completely falls off - leave it and take a photo of the skin patch underneath, noting the date and time. 

Final thoughts

So there we have it! 

A short and sweet summary of patch tests if you suffer from eczema. What have we missed? 

Jump over to our Twitter page and feel free to share your personal stories :) 

With care, 

The yan-yee team


1) Patch testing. (2020). Link

2) Contact dermatitis. (2019). Link

3) Patch testing. (2018). Link 

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