What should you know about purple bump on skin?

A bump may look purple when inflammation, blood close to the surface, or changes in skin pigment affect its appearance. Folliculitis can present as an inflamed bump around a hair follicle, while heat rash can cause clustered irritated spots. Lichen planus may produce itchy purple-toned bumps. Keratosis pilaris and milia are other bump conditions, although their usual appearance differs. A photograph and examination help a clinician judge whether the lesion is superficial, inflamed, bruised, or something that needs closer review. The symptom page on [Skin Bumps](/symptoms/skin-bumps/) gives broader context.

Do not squeeze, scratch, or pick the bump. Wash gently, avoid friction from tight clothing or shaving, and note when it appeared. A cool compress may soothe tenderness or itch. If itching is prominent, a clinician may discuss [Antihistamine Treatment](/treatments/medical-dermatology/oral-antihistamine-therapy/). Do not apply steroid, antibiotic, or bleaching products without advice, especially if the surface is broken. If the lesion remains, changes, or recurs, arrange a skin examination; treatment depends on the diagnosis and may include [Cryotherapy (Lesion Removal)](/treatments/surgical-dermatology/cryotherapy-lesion-removal/).

Seek prompt medical care if the bump grows quickly, becomes very painful, feels hot, drains pus, bleeds without being rubbed, or is surrounded by spreading redness. Seek urgent help for fever, facial swelling, breathing difficulty, or many new purple spots with feeling unwell. A purple bump after a clear minor injury can be monitored briefly, but unexplained or persistent lesions should be examined.

Could this be folliculitis, a heat rash, lichen planus, or another lesion? Does it need dermoscopy, a swab, or a biopsy? Which products should I avoid, and what changes should prompt a return visit?