pediatrics
Measles
Diagnosis of Measles
History and physical examination Serologic testing Viral detection via culture or reverse transcription–polymerase chain reaction (RT-PCR) Measles may be suspected in an exposed patient who has coryza, conjunctivitis, photophobia, and cough but is usually suspected only after the rash appears. Diagnosis is usually clinical, by identifying Koplik spots or the rash in an appropriate clinical context. A complete blood count is unnecessary but, if obtained, may show leukopenia with a relative lymphocytosis. Laboratory confirmation is necessary for public health outbreak control purposes. It is most easily done by demonstration of the presence of measles IgM antibody in an acute serum specimen or by viral culture or RT-PCR of throat swabs, blood, nasopharyngeal swabs, or urine samples. A rise in IgG antibody levels between acute and convalescent sera is highly accurate, but obtaining this information delays diagnosis. All cases of suspected measles should be reported to the local health department even before laboratory confirmation. includes Rubella , Some of these conditions can be distinguished from typical measles as follows: Rubella: A recognizable prodrome is absent, fever and other constitutional symptoms are absent or less severe, postauricular and suboccipital lymph nodes are enlarged (and usually tender), and duration is short. Drug rash: A rash caused by drug hypersensitivity often resembles the measles rash, but a prodrome is absent, there is no cephalocaudal progression or cough, and there is usually a history of recent drug exposure. Roseola infantum: The rash resembles that of measles, but it seldom occurs in children>3 years of age. Initial temperature is usually high, Koplik spots and malaise are absent, and defervescence and rash occur simultaneously. 