You’ve started a new psoriasis treatment, and your skin is finally clearing. But while the uncomfortable plaques, lesions, and rashes may be gone, you might notice new, dark spots on your skin. It’s easy to assume psoriasis has left behind scars, just as acne often does.

However, these darker patches are actually a condition called post-inflammatory hyperpigmentation (PIH). PIH is a common complication of inflammatory skin conditions like psoriasis. In this article, we’ll cover what PIH is and how to treat it. The best way to prevent PIH is by sticking with your psoriasis treatment plan.

What Is Post-Inflammatory Hyperpigmentation?

Your skin gets its color from the pigment melanin. The more melanin you have, the darker your skin tone. Specialized skin cells called melanocytes found deep in the skin produce melanin. Melanocytes are surrounded by other skin cells known as keratinocytes, which help your skin heal.

Psoriasis is a skin disease caused by an overactive immune system. Extra inflammation speeds up the growth and shedding of skin cells, and plaques or lesions build up on the skin’s surface.

The inflammation from psoriasis can cause melanocytes to make more melanin than normal. These cells then move the pigment into the nearby keratinocytes. The overproduction and release of melanin darkens your skin, causing PIH.

Other conditions known to cause PIH include:

• Eczema
• Burns
• Acne
• Allergic reactions

Post-Inflammatory Hyperpigmentation vs. Scarring

There’s a common misconception that psoriasis causes scarring. According to the American Academy of Dermatology, scars form only when the inner layers of your skin — the dermis — are damaged. To repair the wound, skin cells make collagen fibers, which tend to be thicker and less flexible than normal. The tissue formed from collagen is referred to as a scar.

Psoriasis itself doesn’t directly cause scarring. However, if you constantly pick at or scratch your plaques, the action may damage the skin and make it thicker. Scars, however, develop because your body is trying to heal an injury to your skin.

Who Is Likely To Develop Post-Inflammatory Hyperpigmentation?

Anyone can develop PIH anywhere on their skin, but some people are more prone to PIH. Dermatologists have found that people with darker skin tones have a greater chance of developing PIH than those with lighter skin. Hyperpigmentation also tends to be more intense and last longer with darker skin.

Certain medications can also cause PIH, including:

• Antibiotics such as tetracycline
• Antimalarial drugs
• Certain chemotherapies used to treat cancer

How Is Post-Inflammatory Hyperpigmentation Treated?

Talk to your dermatologist if you’re concerned about skin discoloration related to psoriasis. Unfortunately, skin pigmentation from PIH can last from several months to years. Your dermatologist can help by recommending treatments to prevent PIH from getting worse or even developing in the first place.

It’s also important to stick with your psoriasis treatment plan to avoid new plaques. The best way to prevent PIH is by controlling psoriasis. Common therapies for psoriasis include:

• Topical corticosteroid creams and ointments, like hydrocortisone
• Phototherapy (light therapy)
• Topical salicylic acid solutions
• Retinoid gels and creams
• Vitamin D analogs

Sun Protection

If you spend time outdoors, your skin may tan. This is because your melanocytes start making extra pigment to protect your skin cells from the sun’s damaging ultraviolet (UV) rays. Extra sunlight exposure can also make PIH lesions darker, so take extra precautions in the sun.

Be sure to apply a broad-spectrum sunscreen with an SPF of at least 30 before going outside. Studies have also found that tinted sunscreens are especially helpful for people with hyperpigmentation. This is because tinted sunscreen blocks visible light and UV light, which can make PIH worse. Ask your dermatologist about their preferred tinted sunscreen brands. They’ll likely recommend sunscreens with iron oxide, which gives them an orange tint.

Your dermatologist may recommend avoiding direct sunlight whenever possible, especially midday, when the sun is at its highest. If you need to be outside, be sure to wear protective clothing and a hat or carry an umbrella to shield your skin.

Topical Treatments

Treating skin pigmentation from PIH can be difficult and varies from person to person. It’s important to work closely with your dermatologist to find the best treatment plan.

Topical options — treatments applied to your skin — include hydroquinone, a skin-bleaching agent. Hydroquinone stops melanocytes from making more melanin to lighten your skin. You can find creams over the counter (OTC) without a prescription at a drugstore. Your dermatologist can also prescribe a concentrated form of hydroquinone. Be sure to apply sunscreen because the sun can reverse the effects of hydroquinone.

Another topical option, azelaic acid, works like hydroquinone to block melanocytes from making more melanin. Dermatologists usually recommend azelaic acid to treat PIH caused by acne as well. Take a look at the skin care aisle in your drugstore, and you’ll find azelaic acid in OTC creams, gels, and foams. Your dermatologist can prescribe azelaic acid in a higher strength if needed.

Older studies have also found that tretinoin (retinoic acid) can effectively treat PIH. Tretinoin is a form of vitamin A typically used to treat acne, but it’s also used for excess skin pigmentation. Tretinoin is available only by prescription.

Chemical Peels and Laser Therapy

If your PIH symptoms don’t improve with topical therapies, your dermatologist may recommend more intensive treatment. Chemical peels remove the outer skin layers that contain extra pigment. Be sure to find a provider with plenty of experience with this treatment, as chemical peels can cause more skin irritation and make your PIH symptoms worse. Your dermatologist might suggest fruit acid peels as a gentler treatment option.

Some types of laser therapy can also be used to resurface skin and remove areas of hyperpigmentation. As with chemical peels, laser resurfacing can cause inflammation and trigger PIH. It’s important to do your research and choose an experienced provider.

Talk With Others Who Understand

MyPsoriasisTeam is the social network for people with psoriasis and their loved ones. On MyPsoriasisTeam, more than 126,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis.

Have you developed postinflammatory hyperpigmentation after treating your psoriasis? What treatments helped clear your skin? Share your experience in the comments below, or start a conversation by posting on your Activities page.