What is Post-Inflammatory Hyperpigmentation?

Post-inflammatory hyperpigmentation, or PIH, is often the most noticeable type of hyperpigmentation because it's so dark in colouration. But PIH can be lightened.

Hyperpigmentation comes in many shapes and sizes: rounded, patchy, grey, or tan. What always remains consistent is its differentiation from your normal skin tone.

PIH is only one of several classes of hyperpigmentation. The others are:

  • Freckles
  • Age spots, aka liver spots
  • Melasma

What is post-inflammatory hyperpigmentation?

What is hyperpigmentation?

Your skin tone, whether alabaster-fair or ebony-dark, is created by a pigment called melanin. Even people with albinism still have some melanin. A person's individual colouring is created by the intensity of this pigment's expression and the balance of red melanin to brown melanin.

When your skin behaves as normal, this pigment is mixed equally through skin. But external and internal changes can promote a sudden spurt in melanin manufacture. This is what we call 'hyperpigmentation'.


What is post-inflammatory hyperpigmentation?


What is post-inflammatory hyperpigmentation?

Simply put, PIH is skin darkening caused by damage. The stimulation of melanin production is an immune-triggered inflammation that's designed to defend, protect, and heal.

PIH may result from abrasions and other wounds, but the most common cause is acne. It only takes one spot!

A blemish needs three things to flourish:

  1. A collection of dead skin cells, often encouraged by an oily skin type
  2. Spot-causing bacteria such as P. acnes
  3. A pore that traps and incubates the above two

When these three boxes are ticked, a flood of foreign bacteria congregate, and the body senses this as an invasion. In response, the body triggers healing inflammation.

This explains the cause of the eruption, but why do acne lesions also leave behind hyperpigmentation? At present, we know just half of the answer.

Scientists know that when an inflammatory healing response is initiated, increased melanin production will be triggered. Darker forms of melanin help to protect skin from sun damage. It's thought that PIH may be provoked to help defend this weakened area of skin, although the biological reason is not fully understood.

How long does PIH last?

Now that you understand the cause of your PIH, you may be wondering just how long it plans to hang around. The answer to this question depends on:

  1. The severity of your wound, including its depth
  2. Your natural skin tone
  3. Your skin's natural exfoliation rate

If the wound or acne lesion was superficial, PIH should resolve of its own accord in 1 to 3 months. If skin was damaged more significantly, it can take up to a year for a spot of PIH to fade fully.

You do have a degree of control here. You can turn to exfoliating skincare to lighten hyperpigmentation more quickly. To achieve this, you'll need to integrate a gentle, leave-on exfoliating acid, such as glycolic or salicylic acid, into your routine.

We recommend the following for treatment of PIH:

If you're not sure which of these is best suited to treat your PIH, our skincare experts are always very happy to help. You can reach them either by email on service@adorebeauty.com.au or by telephone on 03 9486 7179.


What is post-inflammatory hyperpigmentation?