At a glance
- Term
- PIE (post-inflammatory erythema)
- Area
- Skin
- Measurable from a selfie
- Yes: pink or red flat marks where spots used to be
- Evidence
- Established
- Related
- PIH (post-inflammatory hyperpigmentation), Facial redness, Azelaic acid
Why red marks differ from pigment marks
Post-acne redness and pigment marks need different explanations. PIE involves blood vessel dilation left after inflammation. PIH, or post-inflammatory hyperpigmentation, involves pigment.
That difference explains why pigment-targeting ingredients do little for PIE itself. A product aimed at dark marks doesn't automatically address a pink mark left by a spot.
Facial redness is a broader description. The colour alone doesn't establish that you're looking at PIE.
What a selfie can measure
Measurable from a selfie: yes. A photo can capture the flat pink or red marks where spots used to be. The measurement describes how those marks appear in that image.
The free redness scan maps red tone across the face from one photo. It doesn't establish that every red area is a post-inflammatory mark.
Keep the image and the result together so you can see what the measurement describes.
What established evidence means here
Evidence: established. PIE is a recognised skin change after inflammation, with a blood vessel explanation rather than a pigment explanation.
That status doesn't validate every selfie score or promise that a treatment will clear your marks. The common mistake is reading one number from one photo as a fixed fact about your face. A measurement needs context.
What to do about lingering pink marks
Time, sunscreen and azelaic acid can help. Keep those options separate from the assumption that every leftover mark needs a pigment treatment.
Use photos to document what you see, without turning each score into a reason to change products. A visible red mark and a scan result don't tell you which treatment you personally need.
If you're unsure whether a mark is PIE, ask a doctor before treating it as such.
Questions people ask
- What does PIE stand for in skincare?
- PIE stands for post-inflammatory erythema. It describes flat pink or red marks left after spots on lighter skin.
- Is PIE the same as PIH?
- No. PIE involves blood vessels that remain widened after inflammation, while PIH involves pigment.
- Can a selfie tell me whether I have PIE?
- A selfie can measure visible pink or red marks where spots used to be. It can't confirm their cause or diagnose PIE.
Written from the measurements and ingredient facts on this site, then checked for the usual mistakes. Not medical advice.
Related pages
The closest pages in this section, picked by topic rather than by date.
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