People with psoriasis have to be acutely aware of the chemicals that come in contact with their skin, as some harsher or abrasive substances can cause irritation. Some can even trigger a flare-up.

Scalp psoriasis is one of the most common subtypes of this condition. It can cause small, fine scaling or crusty plaques to develop on the scalp. Scalp psoriasis is different than dandruff, although some shampoos are formulated to treat both.

While psoriasis is a lifelong condition, it doesn’t have to be a life-limiting one. If you want to express yourself with a new and vibrant hair color, or get rid of graying or whitening hair, psoriasis doesn’t have to put the kibosh on your plans.

But there are some things you need to consider, to make sure your skin doesn’t suffer.

For those who want to become a blonde bombshell or a redheaded vixen, it’s not as simple as plucking any bottle from the shelf. Bad reactions can occur when certain substances in the dye come into contact with your scalp or other areas of your skin, such as your neck, shoulders, and face.

Since the roots are where any decent dye job begins, people with psoriasis should take a few extra precautions before dyeing their hair.

Here are a few tips to help you avoid any problems.

If you’re going to have your hair dyed by a professional, let them know about the condition beforehand. If they’re unfamiliar with it, send them some reputable sources for information that can better explain what considerations they need to have with your scalp.

The best approach (in terms of safety and accuracy) is to test the dye or bleach on a small part of your hair before doing all of it. Try it on a patch of hair on the back of your neck. This area is more sensitive and where you’d most likely experience adverse reactions.

If after 24 hours you don’t experience any problems, you should be fine to continue with the rest of your treatment. Make sure to follow the product’s instructions carefully.

Hair dye that comes in contact with your face, including your forehead, can stain your skin and also aggravate it. Some specialists may apply a protective barrier of petroleum jelly around your ears, neck, and other sensitive places.

If your scalp psoriasis is particularly bad, don’t dye your hair until you have the psoriasis under control. Besides causing hair to clump, which makes getting an even dye job that much less likely, it also increases the chances of the dye having an adverse reaction and worsening your condition.

Many beauty products market themselves as “natural.” Since this term isn’t defined by the U.S. Food and Drug Administration — which also oversees cosmetics — manufacturers can use “natural” to mean anything so long as the product didn’t come from outer space.

In this case, you’ll have to do your own sleuthing for worrisome ingredients, just like you do with your moisturizers. Avoid products that are high in alcohol because they can dry out your skin further.

The molecule p-phenylenediamine — listed as the ingredient paraphenylenediamine (PPD) — is the culprit behind most allergic reactions that can occur with hair dye, especially for people who have very sensitive skin. Research also links it with , including respiratory distress.

If you’re concerned about a reaction, avoid products that list this ingredient. Brown or black hair dyes often contain it.

If you want to go red or reddish brown, . For some, it’s a gentler approach. But that doesn’t mean all hennas are safe: avoid dark brown or black henna because it’s often high in PPD, which means it’s more likely to cause an adverse reaction.

Some products that treat scalp psoriasis aren’t good for colored or dyed hair. Interactions between chemicals can create unwanted side effects. The most common is discoloration, but allergic reactions are possible.

Some allergic reactions can occur with hair dye, usually related to PPD. Symptoms of an allergic reaction include skin that becomes red and swollen with possible burning or stinging sensations.

These symptoms often occur within 48 hours of treatment on the scalp, face, or eyelids but can also affect other areas of the body. If you experience extreme pain, swelling, or blistering, consult a doctor immediately, as these are signs of a severe reaction.

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