Measles (Rubeola)

Key Features

Essentials of Diagnosis

• Exposure to measles 9–14 days previously

• Prodrome (2–3 days) of fever, cough, conjunctivitis, and coryza

• Koplik spots (few to many small white papules on a diffusely red base on the buccal mucosa) 1–2 days prior to and after onset of rash

• Maculopapular rash spreading from the face and hairline to the trunk over 3 days and later becoming confluent

• Leukopenia

General Considerations

• One of the most contagious infectious diseases of childhood that presents as a febrile exanthema

• Transmission is via respiratory droplets

• Considered eliminated from the United States in 2000, frequent outbreaks have occurred recently (644 cases in 2014, and 176 cases in the first 2 months of 2015), mainly due to lower vaccine coverage, increasing vaccine hesitancy, and importation

Clinical Findings

• After 2–3 days of a prodrome of sneezing, eyelid edema, tearing, copious coryza, photophobia, and harsh cough, high fever and lethargy become prominent

• Koplik spots are white macular lesions on the buccal mucosa, typically opposite the lower molars

• A discrete maculopapular rash begins when the respiratory symptoms and fever are maximal and spreads quickly from the face to the trunk, coalescing to a bright red

• As rash spreads to the extremities, it fades turning coppery from the face and is completely gone within 6 days; fine desquamation may occur

• Diarrhea can occur in young children and lead to hospitalization

• Persistent fever and cough may signal pneumonia

Diagnosis

Laboratory Findings

• Lymphopenia is characteristic

• Total leukocyte count may fall to 1500/μL

• Diagnosis is usually made by detection of measles IgM antibody in serum drawn at least 3 days after the onset of rash, and may be made later by detection of a significant rise in IgG antibody

• Direct detection of measles antigen by fluorescent antibody staining of nasopharyngeal cells is a useful rapid method.

• Polymerase chain reaction testing of oropharyngeal secretions or urine is extremely sensitive and specific and can detect infection up to 5 days before symptoms

Imaging

• Radiography

  • Chest films often show hyperinflation, perihilar infiltrates, or parenchymal patchy, fluffy densities

  • Secondary consolidation or effusion may be visible

Treatment

• Therapy is supportive

  • Eye care

  • Cough relief (avoid opioid suppressants in infants)

  • Fever reduction (acetaminophen, lukewarm baths; avoid salicylates)

• Vaccination prevents the disease in susceptible exposed individuals if given within 72 hours

• Immunoglobulin (0.25 mL/kg intramuscularly; 0.5 mL/kg if immunocompromised) prevents or modifies measles if given within 6 days

• Secondary bacterial infections should be treated promptly; antimicrobial prophylaxis is not indicated

• Ribavirin is active in vitro and may be useful in infected immunocompromised children

• In malnourished children, vitamin A supplementation should be given to avoid blindness and decrease mortality

Outcome