Measles is a highly contagious viral illness. It causes high fever, cough, runny nose, red eyes, and a spreading red rash. Vaccination protects very well.
How it spreads
- Through the air by coughs and sneezes; the virus can linger in a room for up to two hours.
- People are contagious from about 4 days before the rash until 4 days after it appears.
Symptoms and timeline
- Days 1–3: High fever, cough, runny nose, red/watery eyes; tiny white spots inside the cheeks (Koplik spots).
- Days 3–5: Rash starts on the face/hairline, spreads down to trunk and limbs. Rash is red, flat-to-bumpy, and merges together.
- Fever often peaks when the rash appears.
Why it matters
- Can cause ear infections, pneumonia, and, rarely, brain inflammation (encephalitis).
- More severe in babies, pregnant people, and those with weak immune systems.
When to seek medical care
- Suspected measles exposure plus symptoms—call ahead before going in to avoid exposing others.
- Trouble breathing, very high fever, confusion, dehydration, or if the sick person is a baby or immune-compromised.
Diagnosis and treatment
- Clinicians diagnose by symptoms and confirm with lab tests.
- There’s no specific antiviral for measles; care focuses on fever control, fluids, and rest.
- Vitamin A may be given to children in some situations to reduce complications.
Prevention
- MMR vaccine (measles, mumps, rubella) is very effective:
- Routine: 2 doses in childhood.
- Adults without evidence of immunity should get vaccinated.
- If exposed and not immune: MMR within 72 hours or immune globulin within 6 days can sometimes prevent or lessen illness.
- Stay home and isolate if infected until at least 4 days after rash starts (follow public health advice).