Post-inflammatory erythema is a red, pink, or purple mark on the skin, often caused by acne. It can last for month, but home and medical treatments are effective.

Acne breakouts sometimes leave red, pink, or purple patches in their wake. These stubborn spots are known as post-inflammatory erythema (PIE).

PIE is most likely to occur in people with lighter skin tones, such as skin types I, II, and III on the Fitzpatrick skin phototype scale. PIE doesn’t require treatment to resolve.

PIE can last for several months. There are, however, at-home and medical treatments that can help to eliminate it sooner.

The superficial red, pink, or purple blotches that characterize PIE are caused by dilation, inflammation, or damage to the small blood vessels known as capillaries that reside under skin.

Cystic acne is a common cause of PIE, but any inflammatory skin condition, such as dermatitis and sunburn, can be at fault.

PIE eventually fades on its own, but there are effective treatments that can lessen or eliminate it more quickly.

PIE typically resembles acne spots, though it doesn’t look like blackheads or whiteheads. PIE can be red or pink in color. It may also take on a deep purple tint.

PIE can appear in clusters or as solo dots on skin.

PIE can take up to 6 months to dissipate on its own. If you wish to resolve it more quickly, there are at-home treatments which may help. These include the following.

Topicals

There are several topical medications that can speed up the process.

Topical hydrocortisone

Hydrocortisone is a steroid that reduces inflammation. It’s sometimes used in conjunction with other medications to treat acne, but it should be used with the guidance of a dermatologist, as there’s potential risk for side effects.

Topical vitamin C

The role of vitamin C in acne-induced PIE hasn’t been studied extensively. However, it’s been shown to be effective at reducing erythema caused by ultraviolet B (UVB) rays.

Since it also has skin lightening properties, vitamin C may be beneficial for people who have post-inflammatory hyperpigmentation (PIH) as well as PIE. PIH is a separate skin condition that we’ll cover later in this article.

Niacinamide

Niacinamide is a form of vitamin B3. It reduces inflammation and helps skin retain moisture. Niacinamide may have some benefit for PIE when applied topically. It may also help reduce cystic acne breakouts.

If you have large-scale PIE, or if it doesn’t respond easily to DIY solutions, seeing a dermatologist can help.

Medical treatments

Consider medical treatments if you aren’t satisfied with topical medications.

Laser treatment

Dermatologists use several types of lasers, including intense pulsed light laser and pulsed dye laser, to treat PIE.

These work by pinpointing and eliminating damaged areas of blood vessels under the skin, which reduces inflammation and discoloration. It may take several treatments before you see results.

Microneedling

Microneedling uses a dermaroller of tiny needles to generate a superficial, controlled skin injury. This induces skin to produce new collagen-rich tissue, eliminating surface red spots.

Microneedling also helps break up acne-related scarring. These results may be enhanced when combined with vitamin C serum or topically applied tretinoin.

This should also be used only under the guidance of a dermatologist, as using a home dermaroller with tretinoin can lead to significant irritation, redness, and scarring.

As with laser treatments, you may need to have microneedling done multiple times.

Post-inflammatory hyperpigmentation (PIH) is another potential byproduct of acne and other inflammatory skin conditions. It occurs when skin damage causes an overproduction of melanin.

PIH is most often seen in people with darker skin tones, such as IV, V, and VI on the Fitzpatrick skin phototype scale. However, PIE and PIH can occur simultaneously in many skin types.

PIH differs from PIE in color. PIH is brown, rather than red, pink, or purple. PIH may also be longer lasting than PIE.

PIE can make you feel self-conscious. If you’re not comfortable covering it up with makeup or feel deep distress at having to live with PIE, see your doctor.

A dermatologist can recommend or provide treatment which can speed up your skin’s recovery. Your doctor can also help you to treat the conditions that cause PIE in the first place.

Post-inflammatory erythema (PIE) is the residual red, pink, or purple spots left behind by acne breakouts.

PIE goes away on its own, but it can be resolved more speedily when dermatological treatments are used. At-home treatments may also help reduce or eliminate PIE.