What should you know about mosquito bite hyperpigmentation?

Inflammation can stimulate extra pigment in the skin. Scratching, crusting or repeated bites may deepen the mark and can leave a spot that is brown, grey or darker than the surrounding skin. A flat mark where a healed bite was located fits this pattern, but other causes of [Dark Patches On Skin](/symptoms/dark-patches-on-skin/) can look similar.

The mark itself is usually different from an active bite: it may no longer itch, swell or feel warm. Colour can take time to even out, and new irritation can restart the process.

Avoid picking, use gentle fragrance-free cleansing and cover exposed skin from strong sunlight. A broad-spectrum sunscreen can help prevent the mark becoming more noticeable. Reduce itch promptly with advice from a pharmacist or clinician, and use insect protection to limit fresh inflammation.

If the mark remains bothersome, a clinician may discuss [Skin Brightening Treatment](/treatments/aesthetic-procedures/skin-brightening-treatment/), [Chemical Peel](/treatments/aesthetic-procedures/chemical-peel/), [IPL Photofacial](/treatments/laser-and-energy/ipl-photofacial/), [Picosecond Laser Treatment](/treatments/laser-and-energy/picosecond-laser-treatment/) or [Hydroquinone Treatment](/treatments/medical-dermatology/topical-hydroquinone-therapy/). These are not interchangeable and may irritate some skin types.

Seek assessment if a patch is expanding without a recent bite, becomes raised, painful, scaly or persistently itchy, or develops bleeding or a sore. Get prompt help for swelling of the lips or face, breathing difficulty, widespread hives, fever or increasing redness and drainage.

Ask whether the colour change is post-inflammatory pigment, whether treatment is suitable for your skin tone, how to prevent irritation, and what improvement timeline is realistic.