Also known as rubeola or morbilli, measles is an acute, highly contagious paramyxovirus infection. It is one of the most common and the most serious of all communicable childhood disease.
In temperate zones, incidence is highest in late winter and early spring. Before the availability of measles vaccine, epidemics occurred every 2 to 5 years in large urban areas. Use of the vaccine has reduced he occurrence of measles during childhood; as a result, measles is becoming more prevalent in adolescents and adults.
In the United States, the prognosis is usually excellent.
CAUSES
Measles is spread by direct contact or by contaminated airborne respiratory droplets. The portal of entry is the upper respiratory tract.
SIGNS & SYMPTOMS
Initial symptoms begin and greatest communicability occurs about 11 days after exposure to the virus. This phase lasts from 4 to 5 days; symptoms include fever, malaise, loss of appetite, photophobia, conjunctivitis, hoarseness, and hacking cough.
At the end of this phase, Koplik's spots, the hallmark of the disease, appear. These spots look looke tiny, bluish gray specks surrounded by a red halo. They appear on the oral mucosa opposite the molars and occasionally bleed.
About 5 days after Koplik's spots appear, temperature rises sharply, spots slough off, and and a slightly itchy rash appears. This characteristic rash starts as faint macules behind the ears and on the neck and cheeks.
These macules become papular and red, rapidly spreading over the entire face, neck, eyelids, arms, chest, back, abdomen, and thighs. When the rash reaches the feet (2 to 3 days later), it begins to fade in the same sequence it appeared, leaving a brownish discoloration that disappears in 7 to 10 days.
The disease climax occurs 2 to 3 days after the rash appears and is marked by a temperature of 103° to 105°F, severe cough, puffy red eyes, and nasal discharge About 5 days after the rash appears, other symptoms disappear and communicability ends..
Symptoms are usually mild in patients with partial immunity (conferred by administration of gamma globulin) or infants with transplacental antibodies. more severe symptoms and complications are more likely to develop in young infants, adolescents, adults, and immunocompromised people than in young children.
Atypical measles ma appear in people who received the killed meales vaccine. These individuals are acutely ill with a fever and rash that's most obvious in the arms and legs, or with pulmonary involvement and no skin lesions.
Complications
Severe infection may lead to secondary bacterial infection and to autoimmune reaction or organ invasion by the virus, resulting in otitis media, pneumonia, and encephalitis. Subacute sclerosing panencephalitis (SSPE), a rare and invariable fatal complication, may develop several years after measles. SSPE is less common in people who have received the measles vaccine.
TREATMENT
Therapy consists of bed rest, relief of symptoms, and respiratory isolation throughout the communicable period. Vaporizers, and a warm environment help reduce respiratory irritation, but cough preparations and antibiotics are generally ineffective; antipyretics can reduce fever. Treatment must also combat complications.