Causes of fever with rash in adults

Fever indicates an immune response, while a rash gives clues about what is happening in the skin or blood vessels. A viral illness such as COVID-19 can cause fever, tiredness, cough, sore throat, or body aches, and skin changes may occur in some people. Chickenpox causes itchy spots that develop into fluid-filled blisters and crusts at different stages.

Cellulitis tends to be localised: the skin becomes warm, swollen, painful, and increasingly red. A widespread rash after starting a medicine may be a drug reaction, especially when accompanied by itching or swelling. Brucellosis is a less common possibility after particular animal or unpasteurised food exposures and may cause prolonged fever and sweats. Appearance alone cannot confirm the cause.

Rest, drink fluids, and note the temperature, rash location, and changes over time. Keep a list of every medicine, supplement, and recent exposure, including when each was started. Avoid sharing towels and close contact if a contagious infection is possible. Do not stop an essential prescribed medicine without advice, but seek prompt help if the rash began soon after a new dose or is spreading.

Call emergency services for a non-fading rash with fever, severe headache, neck stiffness, confusion, breathing difficulty, fainting, or unusual drowsiness. Seek urgent assessment for blistering or peeling skin, sores in the mouth or eyes, facial or tongue swelling, rapidly spreading redness, or severe skin pain. Adults who are pregnant or immunocompromised should obtain medical advice early.

Ask whether examination or testing is needed and whether you should avoid work, travel, or close contact. Explain recent medicines, vaccinations, travel, animal contact, food exposures, sexual health concerns, and sick contacts. Ask what fever pattern, rash change, or new symptom should trigger immediate reassessment.