[9][10] Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the front of the neck.

The diagnosis is made based on the results of a rapid antigen detection test or throat culture.

[1][2] The typical signs and symptoms of streptococcal pharyngitis are a sore throat, fever of greater than 38 °C (100 °F), tonsillar exudates (pus on the tonsils), and large cervical lymph nodes.

[3][13] Strep throat is unlikely when any of the symptoms of red eyes, hoarseness, runny nose, or mouth ulcers are present.

[13][15] It is spread by direct, close contact with an infected person; thus crowding, as may be found in the military and schools, increases the rate of transmission.

[15] Of children with no signs or symptoms, 12% carry GAS in their pharynx,[7] and, after treatment, approximately 15% of those remain positive, and are true "carriers".

[19] A number of scoring systems exist to help with diagnosis; however, their use is controversial due to insufficient accuracy.

[8] Testing is not needed in children under three as both group A strep and rheumatic fever are rare, unless a child has a sibling with the disease.

While the rapid strep test is quicker, it has a lower sensitivity (70%) and statistically equal specificity (98%) as a throat culture.

[13] In areas of the world where rheumatic fever is uncommon, a negative rapid strep test is sufficient to rule out the disease.

[13] The primary reason for treatment with antibiotics is to reduce the risk of complications such as rheumatic fever and retropharyngeal abscesses.

[16] The antibiotic of choice in the United States for streptococcal pharyngitis is penicillin V, due to safety, cost, and effectiveness.

[32] In India, where the risk of rheumatic fever is higher, intramuscular benzathine penicillin G is the first choice for treatment.

[38] Streptococcal infections may also lead to acute glomerulonephritis; however, the incidence of this side effect is not reduced by the use of antibiotics.

It is, however, the leading cause of acquired heart disease in India, sub-Saharan Africa, and some parts of Australia.

[8] Complications arising from streptococcal throat infections include: The economic cost of the disease in the United States in children is approximately $350 million annually.