Differentials
Measles
SIGNS / SYMPTOMS
Typically accompanied by a prodrome of significant cough, coryza, and conjunctivitis, and an enanthem consisting of grey-white papules on the buccal mucosa (Koplik's spots).
The exanthem is an erythematous maculopapular eruption that spreads cephalocaudally and usually persists for 1 week before it begins to clear.[19]
INVESTIGATIONS
Diagnosis is usually clinical, based on physical examination and history.
Virus isolation can be obtained from a nasopharyngeal swab, or diagnosis can be confirmed by a serological assay for measles-specific antibodies.[19]
Enterovirus
SIGNS / SYMPTOMS
The exanthem associated with enterovirus (especially echovirus) is a non-specific, maculopapular, erythematous eruption.
Enterovirus often presents as aseptic meningitis.
Other enteroviruses may present with herpangina or vesicular lesions.
Primary differentiation is made based on history, but can be difficult.[20]
INVESTIGATIONS
Polymerase chain reaction or rising serological titres may be used for enterovirus identification in serious cases.
In many uncomplicated cases, history and physical examination are sufficient.[20]
Epstein-Barr virus
SIGNS / SYMPTOMS
The exanthem is non-specific erythematous macules and papules and occasionally urticaria.
The primary differentiation is made based on history.
The eruption of Epstein-Barr virus (EBV) often presents after administration of ampicillin or other antibiotic therapy.[21]
INVESTIGATIONS
Acute EBV is usually diagnosed with a positive heterophile test (or a rapid Monospot), or with specific serology in the child under 4 years of age.
Atypical lymphocytes are common on examination of a peripheral smear.
EBV-specific antibodies are used in patients with a negative Monospot or in cases with atypical symptoms.[21]
Rubella
SIGNS / SYMPTOMS
Presents with a non-specific exanthem of rose-pink macules that spread from the face to the trunk.
Tender cervical, occipital, and/or post-auricular lymphadenopathy is common. Joint involvement is seen in older adolescents and adults.[19]
INVESTIGATIONS
Serology will detect antirubella IgM or a 4-fold increase in antirubella IgG antibodies.[19]
Meningococcaemia
SIGNS / SYMPTOMS
Seizures, fever, and signs of encephalopathy can mimic roseola.
Usually associated with a rapidly progressing purpuric eruption and meningeal signs or sepsis.
INVESTIGATIONS
Cultures of cerebrospinal fluid and blood yield meningococcus.
Use of this content is subject to our disclaimer