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Post-Inflammatory Erythema. What is it and what causes it?

If you have gotten a pimple before then you know what happens when a pimple is finally gone, it leaves a red irritated spot in the area where your pimple was. This red irritated spot is call Post- Inflammatory Erythema, most often referred to as PIE. And sometimes it can be even more stubborn than the original acne.

When there is an inflammation it comes with an acne bump, which can trigger an increase in dilation of blood vessels and vascularity. Which is what gives your skin a red appearance, due to the increased concentration of blood vessels in that spot. In addition to this the redness that goes along with the inflammation can stay on the skin and lead to post-inflammatory erythema.

So, what exactly is Post-Inflammatory Erythema?

PIE or post-inflammatory erythema is the pink or reddish spot that is left behind after the trauma that causes the inflammation on the skin. Not all acne is affected by this i.e. mild, non-inflamed acne, which includes blackheads and whiteheads or comedones acne does not lead to PIE. Acne inflamed papules and pustules is more likely to result in PIE. Papules are red inflamed pimples that are less than 5mm with a white or yellow papule center.

PIE can vary in color and intensity in some cases it can appear light pink while in other cases it can appear red. When the PIE starts to go away the color can change.

PIE can occur anywhere on your body including areas such as neck, chest and back. PIE is more often common in those with fair skin, while those with darker skin experience post-inflammatory hyperpigmentation, more commonly referred to as dark or brown spots.

So what are the causes and prevention?


Acne sufferers commonly have higher amounts of oil production and the oil is thicker and stickier than those with balanced skin. Oil leads to build up in the pores and follicles that blocks the ducts leading to a pimple.


All skin has bacteria but acne sufferers have higher levels of P.acnes bacteria than others. P .acne feeds on the excess oil leading to inflammation, infection and redness which manifests as acne. When the bacteria digest the oil that is trapped it produces fatty acid wastes that leads to irritation. In other words this irritation is PIE, resulting in red or pink spots on the skin.

Harsh products

There are many treatments for acne but it is important not to overdo it and to avoid harsh products and scrubs that can damage our skin, leading to skin irritation, redness and PIE. Also avoid using too many active ingredients at the same time to avoid damaging your skin.


Stop picking or popping that pimple. It can increase the risk of PIE that can lead to more inflammation and redness.

It you have a scab or already popped a pimple, the best way to handle it and prevent PIE is to treat it can you would treat any other would i.e. by facilitating the healing process. If you have a large pimple then it is best to visit a board certified dermatologist for a cortisone injection which can help reduce the breakout.


I am sure some of you must have learned in school that unbalances hormones can result in acne. High levels of testosterone can cause more oil production and lead to breakouts, polycystic ovary syndrome and other such hormonally induced conditions that can trigger acne breakouts.

Excess Dead Skin

A very under-rated cause of PIE is excess dead skin. The excess oil stimulates and aggravates the follicles and contributes to dead skin getting stuck in the pores. Those with acne prone skin produce more skin cells – it can be up to five times more skin cells than normal skin – their skin is also stickier than normal skin. This is called retention hyperkeratosis.

Kaye's Beauty Book is here to help you choose better products that suit your skin, hair and lifestyle. All of the products mentioned are carefully researched and selected to ensure that the most credible information comes to you. If you do buy a product from one of our links, Kaye's Beauty Book may earn a commission.

II DISCLAIMER: Every skin is different, not everything works for everybody. I recommend you test the product before completely using any new product. II

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