Fever blister on the hand: what it may be

A blister on the hand is not the same as a fever; check whether you also have a measured temperature or signs of skin infection. The phrase fever blister can refer to a cold sore, but a hand blister has other possible explanations, including friction, contact irritation or infection. Its location, pain, fluid, redness and spread help determine the next step.

A localised blister with a hot, painful or expanding red area can occur with cellulitis and should be assessed. Chickenpox may cause multiple itchy spots or blisters, often with fever and lesions in different stages. COVID-19, a common cold, acute bronchitis, bronchiolitis and croup are more likely to be considered when fever comes with respiratory symptoms rather than one isolated hand blister. Brucellosis is linked to particular animal or unpasteurised dairy exposures. A photograph cannot replace an examination when the skin is worsening.

Wash your hands, gently clean the area, and keep the blister covered with a clean dressing if it may rub or open. Do not deliberately pop it. Avoid sharing towels, and wash after touching the lesion. If it opens, let fluid drain without peeling away attached skin, then cover it and watch for increasing redness, warmth, swelling, pus or pain. Check your temperature if you feel unwell and follow medicine labels carefully.

Seek prompt care for a rapidly spreading red area, severe pain, pus, red streaks, loss of movement or sensation, or fever with marked weakness. Urgent assessment is also sensible if the blister follows a bite, burn or chemical exposure, or if you have diabetes, poor circulation or a weakened immune system. Get immediate help for confusion, breathing difficulty or a severe allergic reaction.

Ask whether the blister looks infected, whether a swab or other test is needed, how to dress it, and which pain relief is appropriate with your medicines and health conditions.