Mässling

Mässling, or measles in English, is a highly contagious viral illness caused by the measles morbillivirus, a member of the genus Morbillivirus in the Paramyxoviridae family. It spreads mainly through respiratory droplets and aerosols and can remain infectious in the air for several hours. People are typically contagious from about four days before to four days after the appearance of the rash.

After an incubation period of about 10 to 14 days, many individuals develop a fever along with cough, runny nose (coryza) and red, watery eyes (conjunctivitis). Koplik spots—small white patches on the inside of the cheeks—may appear early and are characteristic. The rash usually begins on the face at the hairline and behind the ears, then spreads downward to the trunk and limbs, lasting several days before fading.

Complications are more common in young children and in individuals with malnutrition or immune suppression. These include pneumonia, diarrhea, and otitis media; less commonly, encephalitis and vision problems can occur. A rare but severe late complication is subacute sclerosing panencephalitis (SSPE) years after infection.

Diagnosis is based on clinical presentation and can be confirmed by laboratory testing, such as RT-PCR from respiratory specimens or serology (IgM antibodies).

Treatment is mainly supportive: adequate hydration, fever control, and rest. Vitamin A supplementation is advised in some settings to reduce morbidity and mortality. Prevention relies on vaccination with the MMR vaccine (measles, mumps, and rubella). The first dose is given at 12–15 months, with a second dose later in childhood; high vaccination coverage creates herd immunity and reduces outbreaks.