Measles Differential Diagnoses

Updated: Jun 06, 2019
  • Author: Selina SP Chen, MD, MPH; Chief Editor: Russell W Steele, MD  more...
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Diagnostic Considerations

The diagnosis of measles is usually determined from the classic clinical picture, including the classic triad of cough, coryza, and conjunctivitis; the pathognomonic Koplik spots; and the characteristic cephalocaudal progression of the morbilliform exanthem.

It is worthwhile to be mindful of the syndrome known as atypical measles, which has been described in individuals who were infected with wild measles virus several years after immunization with a killed measles vaccine (a vaccine used in the United States from 1963-1967). This syndrome tends to be more prolonged and severe than regular measles and is marked by a prolonged high fever, pneumonitis, and a rash that begins peripherally and may be urticarial, maculopapular, hemorrhagic, and/or vesicular.

The assumed pathogenesis of atypical measles is hypersensitivity to measles virus in a partially immune host. Laboratory tests reveal a very low measles antibody titer early in the course of the disease, followed soon thereafter by the appearance of an extremely high measles immunoglobulin G (IgG) antibody titer (eg, 1:1,000,000) in the serum.

Other diagnoses to be considered include the following:

  • Kawasaki disease

  • Dengue

  • Serum sickness

  • Syphilis

  • Systemic lupus erythematosus

  • Toxic shock syndrome

Differential Diagnoses