Strep throat is an infectious disease that affects the membranes of the throat and tonsils. It develops mainly in children from 5 to 12 years of age. The disease is also called septic sore throat, acute streptococcal pharyngitis, and acute streptococcal tonsillitis.
Strep throat is caused by bacteria of a type called group A beta-hemolytic streptococci (see Streptococcus ). The bacteria generally spread from person to person through droplets of moisture sprayed from the nose and mouth. People called carriers, who harbor the streptococci but do not have symptoms of disease, can spread strep bacteria. Laboratory tests can confirm the presence of strep bacteria in material from the patient’s throat. See Disease (Spread of infectious diseases) .
Symptoms of strep throat include sore throat, fever, headache, and, in some cases, chills, nausea, and vomiting. The patient usually experiences swelling of the tonsils and of the lymph nodes in the neck. The disease disappears rapidly following treatment with penicillin. Untreated cases generally last four or five days, though some may last as long as two weeks.
Complications can follow strep throat. The infection may spread to the ears, sinuses, lungs, bones, or bloodstream. In other cases, patients later develop rheumatic fever or a kidney disease called acute glomerulonephritis (see Rheumatic fever ; Nephritis ). Prompt treatment with penicillin can prevent the infection from spreading to other parts of the body. Penicillin also ends the risk of rheumatic fever but does not always prevent acute glomerulonephritis.
