How to Identify Acne Marks & Scars: PIE vs PIH

How to Identify Acne Marks & Scars: PIE vs PIH

Acne sucks. But what sucks even more is having your skin clear up, only to find you’ve got to deal with what’s left behind (as if pimples aren’t enough). You might have a few small pink spots, crater-like dents or raised skin toned bumps. To understand how to treat your acne marks & scars, you must first understand what type they are.

There’s more than one type?

Many people don’t know that there are actually several distinct types of residual damage left behind after acne has gone away. It’s important to learn and recognise the difference between Post-Inflammatory Erythema, Post-Inflammatory Hyperpigmentation and true scarring. Each needs a different approach to treatment. Read on to find out how to determine what you have and deal with it.

What is PIE?

No, not the delicious dessert. PIE stands for Post-Inflammatory Erythema. That’s a fancy term for ‘angry blood vessels after damage’. Your skin tried and succeeded in destroying the offending pimple, but unfortunately that heightened blood flow means excess and damaged capillaries. This results in a pinkish flat mark that blanches (disappears) under pressure.

To test whether your marks are PIE, press the bottom of a clear glass against your skin. If you see them disappear, then it’s probably PIE. If they stay visible even under pressure, it’s more likely you’re looking at PIH.

What is PIH?

PIH stands for Post-Inflammatory Hyperpigmentation. Unlike PIE, PIH has to do with melanin levels in your skin. After trauma, our skin tries to protect itself and sometimes this is via a heightened production of melanin. Melanin makes freckles and tans turn brown. It is also what gives colour to their skin of those who are naturally dark. As such, people with naturally deeper skin are more likely to suffer from PIH, due to their tendency to produce melanin.

PIH is flat and can be dark red or brown. It’s sometimes hard to tell apart from PIE. A simple solution is the glass test from above – PIH will not blanch (disappear) under pressure.

What is true scarring?

True acne scarring is damaged tissue left behind after the trauma of acne. You’ll know if you suffer from actual acne scars since your skin will have a change in texture and/or shape. Acne scarring is very difficult to treat yourself, and will require the help of a dermatologist to administer treatments that will resurface and re-level your skin. There are two main sub-types to know.

Atrophic scars

Atrophic are caused by abnormally low collagen production in the skin after trauma. This creates areas that sink down, leaving holes or dents behind. Atrophic scarring comes in several forms – icepick, boxcar and rolling.

Hypertrophic scars

Hypertrophic scars are caused by excess collagen/scar tissue produced after trauma. This then leaves a raised bump above the skin.

How to treat acne marks & scars

Thankfully, modern skin care is able to treat most types of acne marks and scars to one degree or another. Find out how to deal with them.


That’s it for today! Acne and what it leaves behind are totally normal, but people can be deeply affected by it. I think that learning more about something that affects you empowers you to change it.

Did you learn something new about acne marks and scars? What kind do you suffer with? Thanks for reading and I look forward to seeing you here again soon.

The Skin Careless



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