What should you know about measles, mumps, rubella and varicella?

Varicella, also called chickenpox, often causes an itchy rash that changes from spots to fluid-filled blisters and then crusts. New spots can appear while older ones are healing, and fever or tiredness may occur. Measles and rubella have different rash patterns, while mumps more typically affects the salivary glands rather than causing a blistering rash. A rash alone cannot confirm which infection is present. A past varicella infection can later reactivate as shingles, usually in a more localised band.

Avoid scratching, keep nails short, wash hands, and use loose clothing. Do not share towels or close personal items. Keep away from people who are pregnant, very young, or immunocompromised until a clinician advises that it is safe. Arrange a GP consultation for a new blistering rash, especially if there is fever, exposure, pregnancy, or uncertain vaccination history. Ask before using medicines on a child.

Seek urgent help for breathing difficulty, confusion, severe headache, dehydration, a rapidly worsening illness, eye involvement, or blistering around the mouth with inability to drink. Prompt assessment is also needed for severe pain, pus, spreading warmth, or marked redness around blisters, which may signal a complication.

Does this rash fit varicella or another infection? How long should I avoid close contact? Is antiviral treatment appropriate, and what is safe for itch? Should household contacts discuss vaccination or assessment?