What should you know about underarm dark spots?

Friction, shaving, sweat, and deodorant ingredients can irritate the fold and leave darker pigment after the skin heals. Post-inflammatory hyperpigmentation is a common mechanism. Flat brown patches can have other causes, including melasma or sun spots, while fine scale may point toward tinea versicolor.

Look for clues rather than judging the cause from colour alone: note whether the skin is thickened, velvety, scaly, itchy, sore, or changing. Dark patches on skin that appear elsewhere can provide useful context for a clinician.

Wash gently, dry the fold carefully, reduce rubbing, and choose breathable clothing. Stop a product that burns or causes a rash. Avoid picking, hard scrubbing, lemon juice, and unsupervised bleaching products; irritation can leave more pigment.

If the colour persists, a dermatologist may discuss skin brightening treatment, chemical peel, or picosecond laser treatment after confirming the diagnosis. Treating an active rash or infection takes priority over cosmetic pigment procedures.

Arrange an appointment for spots that spread, become thick or velvety, itch persistently, develop scale, or do not settle after suspected irritants are removed. Seek prompt care for bleeding, ulceration, marked pain, drainage, rapidly increasing redness, or fever. Unexplained widespread colour change also warrants review.

What features point to the cause of these spots? Should any infection or inflammation be treated first? Which options are appropriate for my skin tone, and what aftercare will help prevent recurrence?