Measles is a viral illness characterized by a distinctive exanthem and enanthem.
The incidence of measles in the United States has decreased dramatically since the introduction of the measles vaccine; however, outbreaks still occur in both industrialized and nonindustrialized nations due to vaccine fears and nonimmunized persons.
Measles usually presents with a prodrome of fever, cough, coryza, conjunctivitis, and photophobia.
Patients appear acutely ill, and often have cervical and preauricular lymphadenopathy.
Koplik spots, the pathognomonic enanthem composed of small bluish-white macules on the buccal mucosa appear during the prodrome, prior to the exanthem, and provide an opportunity for early diagnosis (Fig. 7.1).
The exanthem appears 3 to 5 days after the onset of the prodromal illness.
Lesions begin as discrete erythematous macules and papules which soon coalesce into areas of confluent erythema starting on the forehead and behind the ears and quickly spread to the neck, trunk, and extremities in a cephalocaudal direction over 2 to 3 days (Fig. 7.2).
The eruption lasts 4 to 7 days and resolves in the same order as it appeared with fine desquamation.
The diagnosis of measles is usually made on clinical grounds.
Although usually unnecessary, serologic testing for measles-specific IgM or IgG can help establish the diagnosis.
The virus can also be detected with PCR techniques from upper respiratory secretions or urine.
Scarlet Fever |
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