What causes bumps on the skin?

Small rough bumps on the outer arms or thighs may fit keratosis pilaris. Itchy prickly clusters after heat and sweating can be heat rash. Pus-filled or tender bumps around hairs may be folliculitis. Smooth white bumps often represent milia, while flat-topped purple or reddish bumps can occur with lichen planus. Sudden itchy raised areas may be hives, especially when individual bumps come and go.

Location, colour, texture, duration, and whether the bumps hurt, itch, drain, or spread are more useful than size alone. Several causes can appear similar without an examination.

Avoid squeezing, picking, harsh scrubs, and heavy products over the area. Keep sweaty skin cool and dry, wear loose clothing, and use gentle cleanser and moisturiser. Pause a newly introduced cosmetic if irritation began afterward. Do not apply steroid, antibiotic, or antifungal creams repeatedly without advice. A clinician can select treatment; options may include Antihistamine Treatment for itch or Cryotherapy (Lesion Removal) for a suitable diagnosed lesion.

Seek urgent help for bumps with facial swelling, breathing difficulty, faintness, or a rapidly spreading blistering rash. Arrange prompt review for fever, severe pain, warmth, pus, red streaks, or fast growth. A persistent bump that bleeds, ulcerates, changes colour, feels hard or fixed, or differs from nearby lesions should be examined even when it does not hurt.

Ask what the bumps most resemble, whether a skin scraping or biopsy is needed, which products to stop, and how to control itch or inflammation without damaging the skin.