Measles: Summary for Health Care Providers

PRODROME

Typically starts three to four days (range one to eight days) before rash onset. Fever typically reaches 101F by day of rash onset.

• Conjunctivitis, may be accompanied by lacrimation and photophobia
• Cough
• Coryza
• Cases typically feel very sick from two days before to at least two days after rash onset
• Koplik’s spots: 1-3 mm whitish, grayish, or bluish white dots on buccal mucosa opposite molar teeth on an erythematous mucosal background (“grains of salt on a red background). Can spread further in mouth. Present two days before to two days after rash onset. Considered pathognomonic for measles.¹ (Images are available online at http://www.lib.uiowa.edu/HARDIN/MD/cdc/measles.html )

RASH

Distribution and progression—starts at hairline ( behind ears) and extends to face and neck on day one, spreads to trunk on day two, and extremities on day three. Usually spares palms and soles. Starts to fade on face on day four, then fades on trunk and extremities. Usually lasts four to seven days.

Character-- maculopapular, erythematous, blanching; becomes confluent in blotches especially in areas where the rash develops first. Palms and soles rarely involved. Bright red, often raised, and “velvety” to touch on days one and two. Begins to fade on days three and four, may turn brownish, followed by fine desquamation.

Chronology Diagram

Minimal clinical criteria: the vast majority of cases are classical and meet the minimum clinical criteria

• Generalized rash lasting three-plus days
• At least one of the following: cough, coryza or conjunctivitis
• Temperature of 101F (38.3C); occurrence of measles with fever lasting beyond the third day of rash suggests possibility of a measles associated complication

Differential diagnosis: includes but not limited to rubella, fifth disease (parvovirus B19), HHV-6 infection, toxic shock, enterovirus or adenovirus infection, mononucleosis, scarlet fever, roseola, Kawasaki’s disease, RMSF, and drug reaction.

INCUBATION PERIOD

About 10 days, but may be seven to18 days from exposure to onset of fever, usually about 14 days until rash appears.

PERIOD OF COMMUNICABILITY

From one day before beginning of the prodromal period (usually about four days before onset) to four days after rash appearance.

DIAGNOSIS

Laboratory testing for measles is available through the Illinois Department of Public Health laboratory and Centers for Disease Control and Prevention. The Department can perform PCR testing. The lab can also submit specimens for a highly sensitive and specific IgM testing to be performed by the CDC.

Anti-measles IgM may be undetectable on the day the rash appears; repeat testing may be indicated.

False positive and negative results have been reported with IgM tests.

Recent measles immunization produces essentially the same antibody responses as natural measles infection.

See attached for information about specimen collection.

REMEMBER

• Report all suspected cases of measles to your local health department immediately.
• Arrange testing through your local health department.
• Isolate suspected cases—health care workers with known immunity to measles should be
  the only staff who have contact with patients suspected of having measles.

In addition to infection control procedures, prevention of the spread of measles depends on prompt immunization of people at risk of exposure or people already exposed who cannot readily provide documentation of measles immunity.