Post-inflammatory erythema (PIE), also known as pie, are pink, red, or purple marks that appear after acne. These marks are different from hyperpigmentation spots and are formed due to skin inflammation. Inflammatory acne, such as papules, pustules, nodules, or cysts, are more likely to leave redness as they heal.

During the healing process, tiny capillaries can become dilated and damaged, resulting in residual redness. PIE can last for months or even years but is usually not permanent like acne scarring. People with fairer or thinner skin can be more susceptible to PIE.

What is the difference between post-inflammatory erythema (PIE) and post-inflammatory hyperpigmentation (PIH)?

Color: PIE is pink/red/purple, while PIH can be tan, brown, or grayish in color.

Cause: PIE involves blood vessels, while PIH results from excess melanin during the healing process.

How to prevent Post-inflamatory Erythema

Manage your acne

Getting your acne under control and reducing inflammatory lesions reduces your chances of developing PIE.

Remember: Avoid popping pimples. Picking or squeezing already inflamed acne can worsen post-inflammatory erythema (PIE).

Be gentle with your skin. Try to avoid physical exfoliants or over-exfoliating and use a chemical exfoliant suitable for your skin type.

Best ways to treat post-inflammatory erythema (PIE)

Incorporating antioxidants such as niacinamide, green tea, and vitamin C can help reduce inflammation.

Salicylic and Mandelic acid can help fade post-inflammatory erythema (PIE) by gently exfoliating, reducing inflammation, and keeping pores clear.

Tranexamic acid decreases redness by suppressing pro-inflammatory cytokines and angiogenesis.

Azelaic acid gently exfoliates the skin and reduces inflammation. It also possesses antibacterial properties that help in treating acne.

Retinoids can help reduce inflammation and increase cell turnover, which can ultimately reduce red marks on the skin.

Sunscreen

UV rays may increase the visibility of post-inflammatory erythema (PIE). Always shield your skin from sun exposure with a gentle broad-spectrum sunscreen of SPF 30 or higher.