Little red blisters on the skin: what to know

Tiny itchy bumps after heat and sweating may fit heat rash. Blisters after a new cosmetic, detergent, adhesive, plant, or metal contact may reflect contact dermatitis. Red, tender skin that feels hot and expands can be a sign of cellulitis and needs medical attention. Sunburn can cause redness, warmth, tenderness, and blistering after excess ultraviolet exposure. Other inflammatory conditions can also produce red, scaly, or blister-like areas, so a photograph or description alone cannot confirm the cause.

Do not pop blisters: the surface helps protect the raw skin beneath. Note the timing, exposures, body area, pain or itch, and whether redness is spreading.

Move away from suspected heat, sun, or a new product. Cool the skin with a clean, damp compress, wear loose clothing, and wash gently. Leave intact blisters covered with a non-stick dressing if they rub against clothing. Avoid ice directly on the skin, fragranced products, and peeling the blister roof. Drink fluids after heat or sun exposure. A pharmacist or clinician can advise on suitable itch or pain relief, especially for children, pregnancy, or sensitive skin.

Obtain prompt medical care for rapidly spreading redness, increasing warmth, severe pain, pus, fever, red streaks, or feeling faint. Emergency help is needed for facial or mouth swelling, trouble breathing, widespread blistering, skin sloughing, or blistering after a new medicine. Large burns and blisters involving the eyes, hands, genitals, or extensive body areas should be assessed.

Ask what the blisters most closely resemble, whether an infection needs treatment, how to dress them, which products or medicines to avoid, and how to protect the area while it heals.