What causes black spots on the legs?

A flat brown or grey mark often reflects post-inflammatory pigmentation after a pimple, folliculitis, scratch, bite, or shaving irritation. A rough spot may be a scab or thickened skin. Several marks around hair follicles can follow repeated ingrown hairs. A spot that is raised, uneven in colour, asymmetrical, enlarging, bleeding, or persistently itchy needs a clinician’s view because not every dark mark is simple pigmentation.

Sun exposure can deepen existing marks, while friction from clothing or hair removal may keep the area irritated. New spots should be considered alongside medicines, skin conditions, and any recent injury.

Do not pick, scratch, squeeze, or scrub the spots. Use gentle cleansing, moisturiser, and sun protection on exposed legs. Pause shaving or waxing over irritated skin and use a clean razor with lubrication when you resume. Photograph a new or changing spot beside a ruler so its shape can be compared over time. A dermatologist can distinguish pigment from a mole or another lesion and discuss treatment only after identifying the cause.

Arrange prompt assessment for a spot that changes quickly, has an irregular border or several colours, repeatedly bleeds, forms an ulcer, or looks different from your other marks. Seek urgent care for rapidly spreading redness, warmth, swelling, pus, fever, or severe pain after an injury. A stable flat mark can usually be reviewed routinely, especially if it does not fade after the original irritation has settled.

Ask whether the mark is pigmentation, a blocked or inflamed follicle, a mole, or another lesion; whether a dermatoscope or biopsy is appropriate; and which hair-removal or pigment treatments are suitable for your skin.