Article: Strep throat

Strep throat (or "Streptococcal pharyngitis", or "Streptococcal Sore Throat") is a form of Group A streptococcal infection that affects the pharynx.

Symptoms

The signs and symptoms of strep throat are red, sore throat with white patches on tonsils, swollen lymph nodes in the neck, fever over 101 Fahrenheit (38 degrees Celsius), and headache. Nausea, vomiting, and abdominal pain are more common in children. Cough is infrequent in older patients, but younger children may experience cold-like symptoms including stuffy noses and sneezing similar to many viral infections. Also, it is common to have extreme shivers/shaking and cold sweats.

Transmission

The illness is caused by the bacterium Streptococcus pyogenes and is spread by direct, close contact with patients via respiratory droplets (coughing or sneezing). Casual contact rarely results in transmission. Rarely, contaminated food, especially milk and milk products, can result in outbreaks. Untreated patients are most infectious for 2-3 weeks after onset of infection. The incubation period, the period after exposure and before symptoms show up, is difficult to establish as some people don't become symptomatic. However, it is thought to be about 1 week.

Diagnosis

The throat of the patient is swabbed for culture or for a rapid strep test (5 to 10 min) which can be done in the doctor's office. A rapid test tests for the presence of typical bacterial antigens in the swab, which are detected by specific antibodies provided in the kit. If the rapid test is negative (that is, normal), a follow-up culture (which takes 24 to 48 hours) may be performed. A negative culture suggests a viral infection, in which case antibiotic treatment should be withheld or discontinued.

In the UK, rapid strep testing is not available to general practitioners and a clinical decision must be made whether to treat while waiting up to 7 days for a swab result to be reported, treat without confirmation from tests, or wait for confirmation. This is criticized for encouraging overuse of antibiotics (see antibiotic resistance).

Treatment

Antibiotic treatment will reduce symptoms slightly, minimize transmission, and reduce the likelihood of complications. Treatment consists of penicillin (orally for 10 days; or a single intramuscular injection of penicillin G). Erythromycin is recommended for penicillin-allergic patients. Second-line antibiotics include amoxicillin, clindamycin, and oral cephalosporins. Although symptoms subside within 4 days even without treatment, it is very important to start treatment within 10 days of onset of symptoms, and to complete the full course of antibiotics to prevent rheumatic fever, a rare but serious complication.

Amoxicillin should be avoided for treatment of a sore throat if bacterial (swab) confirmation has not been obtained since it causes a distinctive rash if the true illness proves to be glandular fever, better known as mononucleosis. This rash is harmless but alarming. Mononucleosis itself, however, can be extremely dangerous if left untreated.