What are the complications of measles and how are they managed?

Complications of Measles

Measles causes serious complications affecting multiple organ systems, with pneumonia being the leading cause of death, followed by acute encephalitis; management focuses on supportive care including vitamin A supplementation and treatment of secondary bacterial infections, as specific antiviral therapy does not exist. 1, 2

Common Complications

Respiratory complications:

• Pneumonia is the most lethal complication and the primary cause of measles-related deaths 1, 3, 4
• Bronchopneumonia occurs frequently and requires aggressive supportive care 1
• Laryngotracheobronchitis (croup) can develop 3
• Adult respiratory distress syndrome (ARDS) may occur in severe cases requiring mechanical ventilation 5
• Spontaneous pneumothorax complicates severe pneumonia, particularly in mechanically ventilated patients 5

Gastrointestinal complications:

• Diarrhea is the most common complication overall 1, 2, 3
• Stomatitis (mouth inflammation) occurs frequently 3
• Severe dehydration may result from diarrhea and requires oral rehydration therapy 2, 3

Ear, nose, and throat complications:

• Middle ear infection (otitis media) is the second most common complication after diarrhea 1, 2

Neurological Complications

Acute encephalitis:

• Occurs in approximately 1 per 1,000 reported measles cases 1, 2, 6
• Survivors often have permanent brain damage and mental retardation 1
• Acute disseminated encephalomyelitis can occur during or shortly after acute illness 3

Subacute sclerosing panencephalitis (SSPE):

• A rare but uniformly fatal degenerative disease of the central nervous system that appears years after measles infection 1, 2
• Typically presents 6-8 years after initial measles infection, with onset generally between ages 5-15 years 7
• Widespread measles vaccination has essentially eliminated SSPE from highly vaccinated populations 1, 2, 7
• Measles inclusion body encephalitis can occur months after infection 3

Hematologic and Other Complications

• Thrombocytopenia (low platelet count) occurs in severe cases 5
• Coagulopathy (bleeding disorders) may develop 5
• Hypocalcemia (low calcium) is common in hospitalized patients 5
• Sepsis from secondary bacterial infections complicates severe disease 5

High-Risk Populations with Increased Complication Rates

Age-related risk:

• Infants, young children, and adults have higher mortality risk than older children and adolescents 1, 2
• The case-fatality rate in the United States is 1-2 per 1,000 reported cases 1, 2, 6
• In developing countries, the case-fatality rate can reach 25% 1, 2

Immunocompromised patients:

• Measles can be severe and prolonged in persons with leukemias, lymphomas, or HIV infection 1
• Disease may occur without the typical rash in immunocompromised individuals 1, 2
• Viral shedding may continue for several weeks after acute illness 1

Pregnant women:

• Measles during pregnancy leads to increased rates of premature labor, spontaneous abortion, and low birth weight infants 1, 2, 6
• Birth defects with no definable pattern have been reported, though causation is not confirmed 1

Malnourished children:

• Malnutrition significantly increases complication severity and mortality 5
• Undernutrition should be considered a strong indication for vaccination, not a contraindication 2

Management of Complications

Vitamin A supplementation (cornerstone of treatment):

• The American Academy of Pediatrics recommends vitamin A supplementation for all children with clinical measles 2
• Children under 12 months: 100,000 IU orally 2
• Children over 12 months: 200,000 IU orally 2
• Repeat dose on day 2 for children with complicated measles 2
• Additional dose 1-4 weeks later for those with vitamin A deficiency eye symptoms 2

Antibiotic therapy:

• Antibiotics should be used for secondary bacterial infections, particularly pneumonia 2, 3
• Early antibiotic treatment is critical in patients requiring intensive care due to prominent secondary bacteremia 5

Respiratory support:

• Mechanical ventilation may be required for severe pneumonia or ARDS 5
• Use lowest possible inspiratory pressure and fraction of inspired oxygen to minimize barotrauma 5
• Accept arterial oxygen pressure less than 60 mm Hg to avoid ventilator-induced lung injury 5

Fluid and nutritional management:

• Oral rehydration therapy for diarrhea 2, 3
• Correction of dehydration and nutritional deficiencies 3, 8

Critical pitfall: No specific antiviral therapy exists for measles treatment; ribavirin and other antivirals have not demonstrated consistent efficacy 3, 4

Prevention of Complications

Vaccination remains the only effective prevention strategy:

• Two doses of MMR vaccine: first at 12-15 months, second at 4-6 years 2, 6, 7
• Post-exposure prophylaxis with MMR vaccine within 72 hours of exposure may prevent or modify disease 6
• Immune globulin (0.25 mL/kg IM, maximum 15 mL) within 6 days of exposure when vaccine is contraindicated 6