Brown spots suddenly appearing on skin

A new brown mark may develop after a bite, rash, pimple, shaving irritation, or minor injury as the skin produces extra pigment during healing. Sun exposure can make existing pigment more visible. Medicines, contact with irritating products, and some inflammatory skin conditions can also alter colour. Several small marks that appear with bruising, fatigue, fever, or bleeding need a broader medical review. The appearance matters: note whether each spot is flat or raised, smooth or scaly, evenly coloured or mixed, and whether it fades with pressure.

Take dated photographs and list new medicines, supplements, skincare products, travel, sun exposure, bites, and recent illnesses. Wash gently, moisturise, and protect exposed areas from sunlight. Do not scratch, peel, or use strong bleaching agents while the cause is unclear. A clinician may examine the spots under magnification and decide whether testing or treatment is needed.

Seek prompt assessment for a spot that enlarges, develops an uneven edge, changes colour, bleeds, crusts, or does not settle. Get urgent medical help for rapidly spreading bruising, facial swelling, breathing difficulty, fever with a hot painful area, or purple-brown spots that do not fade with pressure.

Ask what may have triggered the colour change, whether your medicines or products matter, whether the spots need examination or testing, and which warning signs should bring you back sooner.