Commonly called German measles, rubella is an acute, mildly contagious viral disease that produces a distinctive 3-day rash and lymphadenopathy. It’s most common among children ages 5 to 9, adolescents, and young adults.
Worldwide in distribution, rubella flourishes during spring (particularly in big cities), and epidemics occur sporadically. This disease is self-limiting, and the prognosis is excellent.
The rubella virus is transmitted through contact with the blood, urine, stools, or nasopharyngeal secretions of infected persons and possibly by contact with contaminated articles of clothing. Transplacental transmission, especially in the first trimester of pregnancy, can cause serious birth defects.
Humans are the only known hosts for the rubella virus. The period of communicability lasts from about 10 days before until 5 days after the rash appears.
Signs and symptoms
In children, after an incubation period of 16 to 18 days, an exanthematous, maculopapular rash erupts abruptly. In adolescents and adults, prodromal signs and symptoms—headache, anorexia, malaise, low-grade fever, coryza, lymphadenopathy and, sometimes, conjunctivitis—are the first signs and symptoms. Suboccipital, postauricular, and postcervical lymph node enlargement is a hallmark of rubella.
Typically, the rubella rash begins on the face. This maculopapular eruption spreads rapidly, sometimes covering the trunk and extremities within hours. Small, red, petechial macules on the soft palate (Forschheimer spots) may precede or accompany the rash.
By the end of the 2nd day, the facial rash begins to fade, but the rash on the trunk may be confluent and may be mistaken for scarlet fever. The rash continues to fade in the downward order in which it appeared. The rash generally disappears on the 3rd day, but it may persist for 4 to 5 days—sometimes accompanied by mild coryza and conjunctivitis.