Post-inflammatory erythema, or PIE, is the term for the discoloration left on your skin after deep acne or other skin conditions. Erythema means skin redness. But these marks can be grey, brown, or other colors, too.
What Is Post-Inflammatory Erythema?
PIE can remain even after your acne, eczema, or other skin issues go away. When your skin is injured or irritated, it becomes inflamed (swollen). This inflammation can cause redness, hyperpigmentation, or grey and brown patches on the skin. Rarely, it can cause scarring if picked at, even after the skin has healed.
These marks may be called post-acne erythema when acne is the cause.
Acne can cause pimples on your face, shoulders, back, neck, and chest. There are many factors related to acne, but it’s mainly caused by dead skin cells and oil that clog your pores. This can lead to inflammation and a bacteria infection.
There are different types of acne. Some types are caused by hormone problems and medications. Many things can make acne worse, including:
- Stress
- Certain foods
- Makeup
- Sweat
- Some types of sports equipment
- Personal care products
What Causes Post-Inflammatory Erythema?
Post-inflammatory erythema happens because of the wound healing process. Once the skin is inflamed, irritated, or injured, the wound healing process starts. The process is complex, but it has three steps: inflammation, rebuilding, and strengthening.
When you have a wound, inflammation helps your blood vessels open to allow more oxygen and nutrients in. This helps your injury heal. White blood cells protect your wound from infection.
During the rebuilding stage, your blood cells help make new tissue. Chemicals tell your body to make collagen, a protein that helps new cells grow. Then, over time, the new tissue repairs the wound and gets stronger.
Post-inflammatory erythema happens when blood flow is stopped during inflammation, the first stage. Inflammation, blood vessel dilation, and any damage to those blood vessels can cause red, pink, or discolored marks that appear on your skin. Your skin is usually thinner as it heals and this might make erythema worse.
If the skin doesn’t heal quite right, you might have a loss of collagen or elastin tissue that can cause scars.
Although the main cause of post-inflammatory erythema is acne, anything that causes injury or irritation to your skin can trigger it, says Sonya Kenkare, MD, a dermatologist at Illinois Dermatology Institute in Hinsdale, Illinois. These include:
- Eczema
- Psoriasis
- Sunburn
- Scrapes or other physical injuries
- Bug bites
What Does Post-Inflammatory Erythema Look Like?
Post-inflammatory erythema looks like flat, discolored spots on your skin. If you’re fair-skinned, they may look pink or red. On darker skin, they may look violet or purple.
Is it post-inflammatory erythema or post-inflammatory hyperpigmentation?
Post-inflammatory erythema is a relatively new term. Many people are familiar with post-inflammatory hyperpigmentation, or PIH, but they’re not the same thing.
Whereas post-acne erythema causes red, pink, or purple marks, post-inflammatory hyperpigmentation causes brown, grey, or dark marks on the skin.
Post-inflammatory hyperpigmentation happens when your pigment skin cells make more melanin after an injury or irritation. The darkened spots are a concentration of pigment in one area.
Post-inflammatory erythema tends to happen more often in fair skin, while hyperpigmentation happens more in darker skin.
For people of color especially, post-inflammatory erythema can cause dark spots on your skin, which can mimic the dark spots from post-inflammatory hyperpigmentation.
How Is Post-Inflammatory Erythema Diagnosed?
There’s no single test to tell if you have post-inflammatory erythema. Your doctor will carefully look at your skin and ask questions.
If you already see a skin doctor (dermatologist) to treat another skin problem such as acne, your post-inflammatory erythema may be diagnosed in a follow-up visit. If acne caused the post-inflammatory erythema, you may still see some redness or discoloration, even though your acne may have gotten better.
How to Manage Post-Inflammatory Erythema
Over time, post-inflammatory erythema should go away on its own. Even though it’s temporary, it can last months.
“I often describe post-inflammatory color change to my patients as similar to footprints in the sand, representing the irritation that was created by rash or skin injury,” Kenkare says. “With time, it will fade away without leaving a scar, and there are definitely certain things that help that process.”
But scarring, which can happen alongside post-inflammatory erythema, is permanent. If you notice changes in your skin, make an appointment to get it looked at and treated as soon as possible. Treating acne early on can help your skin heal better.
“Some people may be more prone to post-inflammatory erythema than others, and while it can’t be prevented entirely, there are things that may increase the risk of developing it,” says Marisa Garshick, MD, a board-certified dermatologist at MDCS Dermatology in Manhattan, New York and Englewood, New Jersey.
For example, picking at your skin and using too many skin products often can raise your chances of having post-inflammatory erythema.
Here are some things you can do during and after acne or other irritations that can help treat post-inflammatory erythema.
What to do and what not to do
Don’t pick. The more you squeeze, pop, or pick at your skin, the more inflammation you cause. This leads to a greater chance of having erythema and scars.
Get treated. The sooner you treat acne, the better chance your skin has to heal. There might be less inflammation and less chance of scarring and other problems. Your doctor may prescribe medications that can help.
Don’t scrub. Scrubbing and overwashing irritates your skin. The more you irritate it, the more inflammation you cause. This means you may have a higher risk of having post-inflammatory erythema, scars, or longer-lasting skin irritation.
Use laser resurfacing. Laser resurfacing can sometimes help lower post-inflammatory erythema. The Vbeam laser targets the red blood cells inside your blood vessels to help with residual redness.
Try microneedling (microdermabrasion).Microneedling or microdermabrasion is a technique that uses small needles to prick the skin. This encourages collagen in the skin, which might help get rid of red marks on the surface. This isn’t usually helpful for deep scars.
It can take up to 12 months for results to show, as it takes time for the collagen to affect the skin. The advantage is that the skin doesn’t slough (drop) off the way it does with a chemical peel.
Use topical vitamin C. Vitamin C is anti-inflammatory and helps your body make collagen. This can help improve skin healing, lower inflammation, and avoid redness or pigmentation.
Always wear sunscreen. Acne medications and some treatments such as lasers and acids can make your skin more prone to sun damage. Wear sunscreen to avoid more redness, irritation, and pigmentation.
“The most valuable treatment for post-inflammatory erythema is keeping the skin protected from the sun and practicing gentle skin care over that skin,” Kenkare says.
How Do You Prevent Post-Inflammatory Erythema?
The best way to avoid post-inflammatory erythema is to be gentle with any acne, rashes or wounds. Here are some things you can do to help avoid post-inflammatory erythema.
If you have acne, use pimple patches. These are stickers that you apply directly to acne. They contain ingredients such as salicylic acid, hyaluronic acid, or niacinamide that help dry out your zit and improve skin tone and texture. But they serve another important purpose, too. They help keep you from picking at your pimples, which can lead to very bad inflammation and redness.
Stay safe in the sun. The sun’s UV rays can worsen acne and post-inflammatory erythema. Sunscreen can help keep you protected. Use a mineral sunscreen with at least 8% zinc oxide with SPF 30 whenever you’re outside, even if it’s cold or cloudy. Reapply every two hours. If you’re going to be outdoors in the sun for a long period, consider sun-protective clothing such as a lightweight and long-sleeved shirt, pants, and a wide-brimmed hat.
Take care of cuts and scrapes. Keep the area clean with mild soap and water. To help skin heal, apply petroleum jelly, then cover with a bandage. If it’s a very large area, use hydrogel or silicone gel sheets. Even after the wound has healed, make sure you apply sunscreen to the area. It will help any post-inflammatory erythema fade away faster.
Stick to gentle ingredients. If your skin gets irritated easily, limit the use of products that have exfoliating acids, retinoids, and benzoyl peroxide.
Takeaways
Post-inflammatory erythema is a discolored mark on your skin after an injury or irritation. It’s usually caused by acne, although it can be triggered by skin conditions such as eczema or an injury, such as a cut, scrape, or bug bite. Lasers and vitamin C may help fade these marks, but it can get better on its own. To avoid post-inflammatory erythema and keep it from worsening, don’t pick at your skin, and always wear sunscreen.
FAQs About Post-Inflammatory Erythema
Here are some commonly asked questions about post-inflammatory erythema.
Is post-inflammatory erythema permanent?
Post-inflammatory erythema isn’t permanent. Over time, your blood vessels rebuild themselves, and your skin naturally heals. But if there’s been a lot of damage to these delicate blood vessels, your post-inflammatory erythema may last for a while.
How long does post-inflammatory erythema last?
It can last for months or even years, especially if you don’t treat it.
Does red light therapy help post inflammatory erythema?
Red light therapy is a treatment that uses low levels of red light to help improve your skin. It may help post-inflammatory erythema, as it lowers inflammation, encourages your body to make collagen, and improves skin healing. But it does need multiple sessions over weeks.
