Lab notes  /  Skin  /  Understanding and Treating Post-Inflammatory Erythema (PIE)

Understanding and Treating Post-Inflammatory Erythema (PIE)

And how it differs to Post-Inflammatory Hyperpigmentation (PIH)

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Understanding and Treating Post-Inflammatory Erythema (PIE)
Written byAmelia CranstounContent Editor
Start your 2 minute skin quiz today and one of our aestheticians will create a personalised skincare routine for you!Take the skin quiz

Characterised by flat, red, or pink marks, Post-Inflammatory Erythema (PIE) is a skin concern that often goes unnoticed, but its impact on our skin’s complexion can be significant.

Whether you're an experienced skincare guru or just beginning your skincare journey and struggling to manage new signs of PIE, this guide will equip you with the knowledge and tools you need to achieve clear and radiant skin.

Table of Contents

  • What is Post-Inflammatory Erythema (PIE)?

  • Causes of PIE

  • Differentiating PIE from other Skin Conditions

  • Preventing PIE

  • Treating PIE

  • Skincare Tips for PIE-Prone Skin

What is Post-Inflammatory Erythema (PIE)? 

Post-Inflammatory Erythema (PIE) is a common but often misunderstood skin condition characterised by flat, red, or pink marks that develop after an inflammatory skin injury or trauma such as acne, cuts and burns. These marks are a result of vascular dilation and inflammation caused by the trauma. While PIE is not a true scar, it can last for months or even years if left untreated.

Causes of Post-Inflammatory Erythema (PIE)

PIE typically occurs after various forms of skin trauma, such as:

  • Acne breakouts

  • Picking, squeezing, or popping pimples

  • Burns

  • Cuts

  • Insect bites

When these injuries occur, the body's inflammatory response is triggered, leading to an increase in blood flow to the area and the release of inflammatory mediators. This process can leave behind the telltale red or pink marks associated with PIE.

Differentiating PIE from other Skin Conditions

PIE is often confused with other skin conditions, such as Post-Inflammatory Hyperpigmentation (PIH) and active acne. The primary factor determining whether someone develops PIE or PIH is the way their skin responds to the inflammatory process.

  1. Vascular Response: PIE is characterised by red or pink marks, which indicate an increase in blood flow to the area. When the skin is injured or inflamed, the body's natural response includes the dilation of blood vessels in the affected area. This increased blood flow can lead to redness and is what distinguishes PIE.

  2. PIH involves Melanin PIE does not: In contrast, PIH is characterised by dark brown or discoloured marks. This discolouration is due to an overproduction of melanin, the pigment responsible for the colour of our skin, hair, and eyes. When the skin experiences inflammation or injury, it triggers the release of melanin, leading to the dark spots associated with PIH.

  3. Skin Type and Genetics: The tendency to develop PIE or PIH can also be influenced by a person's skin type and genetics. Individuals with fair or lighter skin are more prone to developing PIE, whereas those with darker skin are more likely to develop PIH due to the increased melanin production. Genetics play a role in determining how the skin responds to inflammation and trauma.

  4. Treatment and Sun Protection: The way these conditions evolve can also be influenced by how they are treated and the level of sun protection used. Sun exposure can worsen both conditions, but it can be particularly detrimental to PIE, making it more prominent. Effective sun protection, like the daily use of sunscreen, can help prevent and manage both conditions.

  5. Inflammatory Severity: The severity of the inflammation or injury can also influence whether someone develops PIE or PIH. More intense inflammation is often associated with a greater likelihood of developing PIE, whereas milder inflammation may result in PIH.

  6. Post-Inflammatory Erythema is Temporary: It's essential to note that PIE is typically temporary and may fade over time, while PIH can persist for a more extended period. PIE marks can take months to years to resolve but often improve gradually as the skin's natural healing processes work to reduce the redness.

To differentiate PIE from these conditions, remember:

  • PIE is flat and pink/red, while PIH is brown or dark brown with hyperpigmentation.

  • Active acne includes inflamed pimples, while PIE occurs after the inflammation has subsided.

Consulting a skin care professional for an accurate diagnosis is recommended if you are unsure about your skin concern.

Treating Post-Inflammatory Erythema (PIE)

To effectively reduce and eventually eliminate PIE marks, consider a combination of targeted skincare products and specific procedures. This guide provides a breakdown of treatments tailored to PIE, offering practical steps for clearer skin.

  • Topical treatments: Skincare-containing ingredients like niacinamide or azelaic acid, can help fade PIE marks.

  • Lasers and light therapies: Procedures like pulsed dye lasers can specifically target and reduce redness associated with PIE.

  • Chemical peels: Chemical peels can exfoliate the skin and promote collagen production, which may help improve the appearance of PIE.

  • Microneedling: Microneedling can stimulate collagen production and help with skin texture and redness.

  • Patience: PIE takes time to fade, and it's crucial to be patient and consistent with your chosen treatment.

Preventing Post-Imflammatory Erythema (PIE)

The best way to manage PIE is through prevention. Here are some tips to help you avoid developing these marks:

  • Hands off: Avoid picking, squeezing, or popping pimples. It can be tempting, but this can exacerbate inflammation and lead to PIE.

  • Sun protection: Use a broad-spectrum sunscreen daily to prevent further skin damage. UV rays can make PIE marks more prominent.

  • Gentle skincare: Use mild, non-comedogenic, and fragrance-free skincare products. Harsh chemicals and fragrances can irritate the skin, leading to inflammation.

  • Spot treatment: For acne-prone skin, use targeted spot treatments to minimise the duration and severity of acne breakouts.

Skincare Tips for PIEprine skin

Harley Street Dermatologist and Renude’s Dermatology Advisor, Dr. Justine Kluk says: 

“Post-inflammatory erythema is a therapeutic challenge because once they appear marks can take many months to fade. This is why early and effective treatment of the acne itself is so important. It reduces the chances of developing downstream effects like PIE.”

Maintaining healthy skin is key to preventing PIE and other skin conditions. Here are some general skincare tips to follow:

  • Gentle cleansing: Use a mild, hydrating cleanser to avoid further skin irritation.

  • Moisturise: Keep your skin hydrated with a non-comedogenic moisturiser.

  • Sun protection: Apply sunscreen every morning, even on cloudy days.

  • Avoid harsh products: Steer clear of products with alcohol, strong acids, and fragrances.

  • Consult a professional: If you have persistent skin concerns, it's always best to consult a professional such as a Renude aesthetician for professional guidance.

Post-Inflammatory Erythema (PIE) can be a challenging skin concern, but with the right knowledge and skincare practices, you can effectively prevent, treat, and manage it. Skincare enthusiasts should prioritise a gentle and consistent routine, with an emphasis on prevention through sun protection, hands-off practices, and the use of appropriate skincare products.

Remember that patience is key when dealing with PIE, as these marks can take time to fade. Consulting a dermatologist can provide valuable insights into your specific skin needs and treatment options. By following these guidelines and being proactive in your skincare routine, you can achieve clear and radiant skin, even if you have experienced the effects of PIE.

Amelia CranstounContent Editor
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Amelia CranstounContent Editor
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