What should you know about raised bumps on your arm?

Raised bumps on your arm may come from irritated follicles, heat, keratosis pilaris, or another skin condition, so examine their pattern and symptoms. Raised bumps may be flesh-coloured, red, itchy, tender, rough, or filled with fluid. Note when they appeared, whether they cluster around hairs, and whether heat, sweating, a new product, shaving, or friction preceded them.

Small rough bumps on the outer upper arm often fit keratosis pilaris, while bumps centred on hairs can fit folliculitis. Heat and sweating may trigger heat rash. A clinician may also consider lichen planus or milia when the colour, surface, or distribution is unusual. These conditions are different, so a visual examination matters.

Wash gently, avoid picking or squeezing, and pause shaving or scrubbing over the area. Use a plain moisturiser if the skin feels rough or dry, and keep sweaty skin cool and dry. Record changes in size, colour, pain, itch, and spread. Treatment depends on the cause; an antihistamine treatment may help itch in selected cases, while cryotherapy is reserved for particular diagnosed lesions.

Arrange medical advice if the bumps rapidly spread, become hot or painful, drain pus, form blisters, or come with fever. Seek prompt assessment for a firm or bleeding bump that does not settle, or for any lesion that changes noticeably. Bring a list of new medicines and products, and mention possible insect exposure.

Could the bumps be follicle-related or keratosis pilaris? Which products should I stop or use? Do I need treatment for itch, inflammation, or an individual lesion? What change should prompt a review?