Every wound goes through the inflammatory phase to heal. During the inflammatory phase, excessive melanin is produced and deposited around the wound. The wound area becomes darker and this excessive pigmentation may stay on long after the wound has recovered, up to 1 or 2 years. PIH is not scarring and will resolve on its own even without treatment. PIH is made worse if exposed to the sun.
What are the risk factors for developing PIH:
- Deep wound (beyond epidermis)
- Heat damage to skin
- Prolonged wound healing time due to poor wound care
- Dark-skinned individuals
Insect bites, eczema and acne can all heal with PIH. The same goes to almost all aesthetic procedures that induce controlled injuries to the skin. The risk and duration of PIH increases as the procedures get more aggressive.
For example, a small needle prick to administer solution will heal uneventfully the next day. But a small mole removed with laser heat may heal with scabs after 5-7 days, then proceed to darken with PIH for a few weeks before the PIH slowly fades.
For light-skinned individuals, PIH is usually not much of a concern. The risk for wounds to develop PIH is very low. Even if they do get PIH, it’s only transient.
On the other hand, darker-skinned individuals have to be more cautious and selective when it comes to aesthetic procedures like lasers and chemical peeling. This is because they may end up with PIH that lasts months. It is therefore imperative for the treating physician to first prime their skin with products and / or medication before the procedure to reduce such risks.
Sun protection is emphasized again and again pre and post procedure until it becomes a norm in clients’ daily routine. Last but not least, even if clients do end up with PIH, fret not as the physician is well-equipped with an armamentarium to treat the PIH.