scarlet fever or scarlatina, an acute, communicable infection, caused by group A hemolytic streptococcal bacteria (see streptococcus) that produce an erythrogenic toxin. The disease is now uncommon, probably because antibiotic therapy has lessened the likelihood of spread. It occurs in young children, usually between two and eight years of age, and is spread by droplet spray from carriers and from individuals who have contracted the disease. The incubation period is from three to five days, and infectivity lasts about two weeks. Scarlet fever may be mild or severe, but it is rarely fatal if treated. Typical symptoms are sore throat, headache, fever, flushed face with a ring of pallor about the mouth, red spots in the mouth, coated tongue with raw beefy appearance and inflamed papillae underneath it (strawberry tongue), and a characteristic eruption on the body. The streptococcal bacterium that causes scarlet fever is identical to the streptococcal pharyngitis (strep throat) organism, the difference being the production of a toxin to which the patient is susceptible in the case of scarlet fever. Severe infections are occasionally complicated by rheumatic fever, kidney disease, ear infection, pneumonia, meningitis, or encephalitis. Mild scarlet fever requires only bed rest, antibiotics, analgesics or antipyretics, and symptomatic treatment. Antibiotics, immune serum, and antitoxin may be required for severe cases.