A woman with post-inflammatory erythema from acne lesions

Post-Inflammatory Erythema (PIE): Treating After-Acne Red Spots

The name might not be familiar — but those frustrating pink spots that appear post-acne probably are. Here's what do.


4 minute read

Ever wonder why you get a pink or red spot as your acne heals? These post-pimple marks — technically called post-inflammatory erythema (PIE) — can seemingly take forever to fade. But here's the good news: there are ways to avoid and manage PIE. 

With the help of dermatologist Sandra Lee, MD (aka Dr. Pimple Popper), we’re answering all of your questions: what causes those red spots to form in the first place, why some of them turn brown, and most importantly, what you can do to treat and prevent post-inflammatory erythema.


What is post-inflammatory erythema?

If you’ve never heard of PIE before, that’s because the term was only coined ten years ago, to distinguish pink, red or purple post-acne lesions from other types of post-breakout dark marks. They appear as a wound is healing, particularly in cases of inflammatory breakouts (like papules, pustules and cysts). That's why PIE is sometimes referred to as post-acne erythema.

You can think of pimples as mini-wounds. When your immune system springs into action to fight off acne-causing bacteria, inflammation results. As the skin begins to heal, tiny blood vessels (aka capillaries) can dilate and become damaged — resulting in that telltale redness.

Even though post-inflammatory erythema can linger for months (or years), its temporary nature sets it apart from true acne scarring.

Dr. Pimple Popper's PIE Picks

What causes post-acne erythema?

Not everyone who has acne will develop PIE, and the severity can vary from person to person — even from pimple to pimple. That’s because post-inflammatory erythema is dependent on inflammation: so if you have non-inflammatory acne (blackheads and whiteheads), you’re not likely to develop pink or red marks. But if your breakouts include inflammatory papules, pustules, nodules or cysts, chances are you’ll see some of that redness as they heal.

People with fair skin — Fitzpatrick types I, II and III — tend to be more susceptible to post-acne erythema. The same holds true for those with thinner skin, since healing skin tends to be even thinner to begin with. This makes blood vessels become even more apparent during the skin repair process.

What’s the difference between PIE and PIH?

So here’s how post-inflammatory erythema differs from post-inflammatory hyperpigmentation:

  • Color: PIE is pink to red, while PIH can be tan, brown, or grayish looking.
  • Cause: PIE involves blood vessels, whereas PIH results from excess melanin deposited during healing.
  • Candidate: Generally speaking, fair-skinned people are more likely to experience PIE, whereas darker-skinned types are more likely to get PIH.

How do you prevent post-inflammatory erythema?

According to Dr. Lee, the best way to handle post-inflammatory erythema is to minimize the inflammation that causes it. Here are her top tips for avoiding PIE:

Treat your acne

Getting your acne under control means that you’re less likely to wind up with breakout-induced inflammation in the first place. Use an acne regimen that treats acne at every stage, since non-inflammatory comedones lead to inflammatory breakouts.

Try: SLMD Acne System

Avoid popping your pimples

Dr. Lee consistently warns about this, since popping not only damages skin, it can spread your acne. Picking and squeezing are off-limits, too, as anything that might make the wound worse can also make PIE worse.

Try: SLMD Salicylic Acid Pimple Patches

Be gentle with your skin

You want to avoid causing any additional trauma to the skin — including micro tears that you can't even see. Use a chemical exfoliant as your skin tolerates, since scrubbing or over-exfoliating can exacerbate irritation and inflammation, making red marks worse.

Try: SLMD AHA/BHA Swipes

    What’s the best way to treat post-acne erythema?

    In many cases, notes Dr. Lee, PIE heals on its own over time. If you want to speed the process, there are a few methods you can try:

    Spot treat your pimples

    Dr. Lee recommends using maximum-strength benzoyl peroxide to treat active pimples by killing bacteria. Once it starts to heal, you can switch to salicylic acid, which helps exfoliate gently. This beta hydroxy acid can help reduce inflammation and clear out pore-clogging debris, speeding healing.

    Try: SLMD BP Acne Spot Treatment, SA Acne Spot Treatment

    Try topical retinoids

    Tretinoin and its over-the-counter cousin, retinol, helps quell inflammation and increase cell turnover, which can reduce red marks. But be patient: retinoids can take weeks to months to make their full impact.

    Try: SLMD Retinol Resurfacing Serum

    Incorporate antioxidants

    Ingredients like vitamin E, niacinamide and vitamin C neutralize the free radicals that damage skin and impede the healing process. Over time, using them can help brighten and calm down irritated skin.

    Try: SLMD Bright Future Vitamin C Serum

    Wear sunscreen — always

    This one’s a no-brainer, since we all know that UV exposure results in red skin, which is exactly what we’re trying to avoid with PIE. Look for formulas created especially for acne-prone skin.

    Try: SLMD Dual Defender SPF 30

    Book a laser treatment

    According to Dr. Lee, there are several different in-office treatments that can help fade your PIE — as long as your doctor knows what they're doing. an inexperienced practitioner, she cautions, could make your condition worse. Talk to your dermatologist to determine if you’re a candidate for an in-office procedure like IPL or PDL to target the redness.

      Dr Sandra Lee

      Dr. Lee's Last Word

      A lot of patients ask me about how to get rid of those lingering marks that take so long to go away once a pimple heals. Red marks are signs of post-inflammatory erythema, and typically they fade away on their own. Treating your acne and not popping your pimples is the best way to support your skin’s healing process and keep redness and hyperpigmentation to a minimum.


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