Measles

Measles symptoms appear in two stages. In the early stage (days 1-3), you'll notice high fever (often above 104°F), a persistent cough, runny nose, and red, watery eyes — symptoms that can be mistaken for a bad cold. Around days 2-4, tiny white spots called Koplik spots appear inside the cheeks. The hallmark red, blotchy rash then erupts on the face and spreads down the body over 3-5 days, often accompanied by worsening fever. Complications such as ear infections, pneumonia, and, rarely, brain swelling can follow.

Measles is spread almost entirely through the air. When an infected person coughs, sneezes, or even breathes, tiny virus-carrying droplets are released and can linger in the air or on surfaces for up to two hours. You can contract measles simply by walking into a room where an infected person was recently present, without any direct contact. Touching a contaminated surface and then touching your mouth or nose can also transmit the virus.

From the first symptoms to recovery, measles typically lasts about 7 to 10 days. The prodrome phase — fever, cough, runny nose, and red eyes — begins roughly 10 to 14 days after exposure and lasts 2-4 days. The rash then appears and persists for 5-6 days before fading. Most otherwise healthy people recover fully within two weeks, but complications like pneumonia or ear infections can extend illness significantly, especially in young children, pregnant women, and immunocompromised individuals.

Yes — measles is one of the most contagious infectious diseases ever identified. Its basic reproduction number (R0) is estimated at 12-18, meaning one infected person can, on average, infect 12 to 18 others in a susceptible population. An infected person is contagious from about 4 days before the rash appears through 4 days after, which means people often spread measles before they even know they have it. Approximately 90% of non-immune people exposed to the virus will become infected.

The United States is experiencing its largest measles outbreak in decades in 2026, with cases reported in multiple states including Texas, New Mexico, Kansas, Ohio, Indiana, and Michigan. The surge is driven by declining vaccination rates in certain communities, enabling the virus to spread among unvaccinated children and adults. Public health authorities are urging anyone who has not received two doses of the MMR vaccine to get vaccinated promptly, and are advising parents to verify their children's vaccination status before school enrollment.

The measles rash has several distinguishing features: it begins as flat, red spots on the forehead and behind the ears before spreading downward to the neck, trunk, arms, legs, and feet over 3-4 days, and spots often merge into large blotches. Critically, it appears alongside high fever (104°F+), cough, runny nose, and red eyes — not in isolation. Other rashes like roseola start after a fever breaks, chickenpox produces itchy blisters scattered across the body, and allergic rashes are typically itchy without respiratory symptoms. If you suspect measles, call your doctor before visiting a clinic to avoid exposing others in waiting rooms.