What should you know about black round spots on skin?

Possible explanations include flat pigment left after a pimple or bite, a clogged pore, a small bruise, a mark around an inflamed hair, or a separate pigmented lesion. Some causes are harmless, but a changing dark spot cannot be classified safely by colour alone.

Flat marks that appear where pimples settled can represent post-inflammatory pigmentation. Acne often presents with a mixture of blackheads, whiteheads, and inflamed spots; folliculitis presents with bumps arising around hairs. These conditions can leave darker marks after active inflammation improves.

Look at whether each spot is flat or raised, smooth or scaly, uniform or varied in colour, and sharply or irregularly bordered. Also note whether several appeared together, whether they blanch when pressed, and whether medicines, injury, hair removal, or a new skin product preceded them.

Do not squeeze, cut, or bleach an unexplained spot. Clean gently, moisturise if the skin is dry, and use sun protection on exposed areas because sunlight can deepen pigment after inflammation. Take dated photographs in similar lighting, including one that shows scale.

For several pimple-like marks, choose non-comedogenic skin and hair products and reduce friction from tight clothing or equipment. Introduce only one new active product at a time and stop it if burning, swelling, or blistering develops.

Arrange an examination if one spot is new and unlike the others, steadily enlarges, has an irregular edge or several colours, becomes firm, or keeps itching, crusting, or bleeding. A clinician can inspect it closely and decide whether sampling is appropriate.

Seek prompt care for many dark purple or black spots that appear suddenly without injury, especially with fever, unusual bleeding, severe headache, breathing difficulty, or feeling acutely unwell. Sudden blackening after injury or loss of circulation also needs urgent assessment.

Ask what features distinguish pigment after inflammation from an active follicle problem or a separate lesion. Clarify whether any spot needs close-up photography, follow-up measurement, or a sample, and which treatments will minimise further irritation.