Hypopigmentation: Loss of Skin Color and What to Watch For
Quick facts
- Definition
- Reduced skin color in an area, from less melanin or fewer melanocytes.
- Difference from acute blanching
- Acute blanching right after injection suggests ischemia and is an emergency; hypopigmentation is slow.
- Associated situations
- Inflammation, scarring, burns, lasers, peels and some skin diseases.
- Attention
- Skin of higher phototypes shows the loss of color with more contrast.
Hypopigmentation is the reduction of skin color in an area, due to decreased melanin production or fewer melanocytes. It appears as a patch lighter than the surrounding skin. It is the opposite of post-inflammatory hyperpigmentation, in which the patch darkens.
When does it appear?
It can arise after inflammation, scarring, a burn, the use of energy (laser, light) and some skin diseases. It can also be a pre-existing condition, as in vitiligo. The epidermis is where the melanocytes sit, and any injury to that layer can change the color.
How do you tell it apart from an emergency?
The key is timing. Sudden blanching of the skin near the injection site, sometimes with pain, should be read as possible ischemia and handled at once. See skin blanching and vascular occlusion.
| Picture | When it appears | Action |
|---|---|---|
| Acute blanching | During or right after the injection | Emergency: stop and treat the suspicion |
| Hypopigmentation | Days to weeks later | Assess the cause and follow up |
Why does dark skin call for extra attention?
In higher phototypes, loss of color is more visible, and inflammation easily changes the pigment. The medical history should ask about scars that changed color and about earlier patches. More in HOF on Black skin.
Frequently asked questions
Is hypopigmentation the same as skin blanching after an injection?
No. Sudden blanching during or right after the injection can indicate compromised circulation and calls for immediate action. Hypopigmentation is a gradual loss of color that appears days or weeks later.