What are the symptoms of measles?

Public health officials say measles typically begins with a high fever, often reaching 104°F (40°C) or higher, followed by a constellation of respiratory and mucosal symptoms. The early phase includes cough, runny nose (coryza), and red, watery eyes (conjunctivitis). Clinicians note small white lesions on the buccal mucosa, known as Koplik spots, that may appear before the rash and help establish diagnosis.

After three to five days of prodrome, a red, blotchy maculopapular rash emerges, usually starting at the hairline and behind the ears, then spreading downward to the face, trunk and extremities. The rash typically lasts about five to six days and fades in the same top-to-bottom pattern. Additional signs can include marked fatigue, loss of appetite and sensitivity to light. Because measles is highly contagious, people are infectious from roughly four days before rash onset to four days after.

Complications are more common in young children, pregnant people and immunocompromised patients and can include otitis media, pneumonia and, in rare cases, encephalitis. Severe illness may require hospitalization. Laboratory confirmation is achieved through viral detection by PCR or serologic testing for measles-specific IgM antibodies, which public health laboratories perform to confirm suspected cases.

Medical and public health authorities emphasize prevention through vaccination with the measles-mumps-rubella (MMR) vaccine, given routinely with a first dose at 12–15 months of age and a second dose at 4–6 years. Anyone who develops compatible symptoms, or who was exposed and lacks documentation of immunity, should seek prompt evaluation and avoid contact with others, particularly vulnerable populations. Health agencies and infectious disease specialists provide guidance to clinicians managing suspected cases.

Rapid identification, laboratory confirmation and isolation remain critical to limiting transmission; clinicians are advised to report suspected infections to public health authorities so contact tracing and post-exposure prophylaxis can protect at-risk contacts and prevent outbreaks.