Pictures of rubella and disease information have been excerpted from the VisualDx® clinical decision support system as a public health service. Additional information, including symptoms, diagnostic pearls, differential diagnosis, best tests, and management pearls, is available in VisualDx.

Full Clinical Write-up


Rubella (German measles) is caused by the rubella virus, which is an RNA virus in the Togaviridae family. Transmission is through the respiratory route. Its incubation period is 14-21 days. A prodrome of irritability, malaise, mild conjunctivitis, headache, fever, adenopathy, and minimal respiratory symptoms may appear 1-7 days prior to the cutaneous eruption. An exanthematous eruption starts on the face, spreads caudally, becomes generalized in 24 hours, and then typically disappears within 3 days. The palms and soles are typically, but not always, spared. This rash may be absent in as many as 25% of cases.

Infection in the United States is rare, owing to widespread vaccination. There is a higher incidence in confined populations such as military bases and schools. The disease is more common in the spring and summer. Arthralgias and mild arthritis, splenomegaly, thrombocytopenia, and testicular pain are sometimes seen. Encephalitis occurs in 1 out of 6000 cases. Pain on lateral or upward eye movement is common in this disorder. Thrombocytopenic purpura is also a rare complication.

Even in the immunocompromised host, rubella is usually a benign illness. The major impact of rubella is on the fetus of a pregnant patient and is one of the TORCH (toxoplasmosis, other [syphilisvaricella zosterparvovirus B19], rubella, cytomegalovirus, and herpes simplex) diseases. These disorders can cause fetal heart and eye malformations, cataracts, deafness, intellectual disability, thrombocytopenic purpura, hepatosplenomegaly, intrauterine growth retardation, interstitial pneumoniamyocarditis, myocardial necrosis, and metaphyseal bone lesions.

Look For

Pink macules and small papules that later coalesce and often desquamate. Purpura can be seen. Pink macules begin on the face. Within one day, the rash fades from the face and spreads centrifugally to the trunk and extremities. The pink macules coalesce on the trunk but remain discrete on the extremities. The rash may be absent in as many as 25% of cases.

Pinpoint petechiae of the soft palate may be observed (Forchheimer spots), typically at the end of the prodrome or start of the cutaneous eruption.

Impact of skin color on clinical presentation: The red color of macules and papules is more readily appreciated in lighter skin colors. Their appearance may be subtle in darker skin colors, and the textural change of fine papules may be the sole clinical finding. A faint pink, deep red, or violaceous hue may be seen. Applying brief gentle pressure with a fingertip or microscope slide to blanch involved skin may accentuate subtle erythema as the pressure is withdrawn. Use of a bright light may further illuminate any subtle color changes present. Postinflammatory hyperpigmentation is more prominent and lasts longer in darker skin colors.

The full text and image collection is available to VisualDx subscribers.

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