Symptoms 

In general, signs and symptoms of strep throat include:
•    Throat pain
•    Difficulty swallowing
•    Red and swollen tonsils, sometimes with white patches or streaks of pus
•    Swollen, tender lymph glands (nodes) in your neck
•    Fever
•    Headache
•    Rash
•    Stomachache and sometimes vomiting, especially in younger children

It's possible for you or your child to have many of these signs and symptoms, but not have strep throat. The cause of these signs and symptoms could be a virus, tonsillitis or other illnesses. That's why your doctor generally tests specifically for strep throat.

It's also possible to have the bacteria that cause strep in your throat without having a sore throat. Some people are carriers of strep, which means they can pass the bacteria on to others, but the bacteria no longer make them sick.

Causes

The cause of strep throat is bacteria known as Streptococcus pyogenes, or group A beta-hemolytic streptococcus.
Streptococcal bacteria are highly contagious. They can spread through airborne droplets when someone with the infection coughs or sneezes. You can also pick up the bacteria from a doorknob or other surface and transfer them to your nose or mouth. Kitchen utensils and bathroom objects are other common sources of infection transmission.

Risk factors

Strep throat occurs most commonly in children between the ages of 5 and 15.
Children with recurrent strep throat whose tonsils are intact are more than three times as likely to develop subsequent episodes of strep throat as are children who've had their tonsils removed, according to a 2006 Mayo Clinic study.
While strep throat can occur at any time of the year, it tends to circulate in late fall, winter and early spring. Strep bacteria flourish wherever groups of people are in close contact. That's why the infection spreads easily among family members, in schools and in child care settings.
When to seek medical advice
Call your doctor if you or your child has any of these signs and symptoms:
•    A sore throat without a cold or runny nose
•    A sore throat accompanied by tender, swollen lymph glands (nodes)
•    A sore throat that lasts longer than 48 hours
•    A fever higher than 103 F in older children, or any fever lasting longer than 48 hours
•    Rash
•    Joint pain
•    Problems breathing or difficulty swallowing anything, including saliva

Call your doctor if you or your child doesn't feel better after taking antibiotics for 24 to 48 hours. Sometimes problems occur even after you or your child has finished treatment for strep throat.
Call your doctor if your child develops a fever — or has pain or swelling in the joints, shortness of breath or a rash — after a strep infection, even as long as three weeks after a strep infection. These can be indicators of rheumatic fever. Cola-colored urine after a strep throat infection may indicate kidney inflammation.