“Strep throat,” or Group A Beta-hemolytic Streptococcal Pharyngitis (GABHS pharyngitis) as it is known in medical jargon, is caused by a bacterium called Streptococcus pyogenes, a member of the Group A family of the Streptococcus genus. Pharyngitis is most prevalent in the late fall, winter and early spring (as if you couldn’t tell based on the number of children out sick with strep in the last few weeks). It is spread through contact with another person who has strep throat. A recent article in the New England Journal of Medicine indicated that less than 50% of family members of a child with strep will end up catching the disease. The incubation period of strep is two to five days, and children will remain contagious until slightly less than 24 hours after the start of antibiotic therapy. The disease is most common in children ages 5-15 and is rare in children under the age of 3.
The symptoms of a streptococcal throat infection generally include sore throat and fever. However, other symptoms may include headache, stomach pain, vomiting and generalized aches and pains. It should be stressed that a sore throat is not a requirement for having streptococcal pharyngitis. Occasionally, strep pharyngitis will also cause a red, bumpy, itchy rash on the chest and back. When this occurs, the disease in known as scarlet fever (it sounds scary, but has no additional side effects over regular strep). Additionally, the GABHS bacteria can also cause a skin disease known as impetigo. Impetigo produces red pimples on the skin that often have a golden or honey-colored scab over them. The disease is spread by contact with other infected children, and one can have impetigo and pharyngitis simultaneously.
The diagnosis of strep pharyngitis is virtually impossible via physical exam alone. Often, children will have a red throat with enlarged tonsils covered with pus. Additionally, children also often have painful, swollen glands on the neck. However, occasionally, a child will have none of these symptoms yet still have the disease. Therefore, the only way to make the diagnosis is through either a rapid strep test, which detects certain proteins on the bacterium’s surface, or through a throat culture where actual growth of the bacteria on a special agar Petri dish can be seen.
Streptococcal pharyngitis is generally easily treated with a 10-day course of everyone’s favorite antibiotic, amoxicillin. It may also be treated with a single shot of penicillin. However, in recent years antibiotic resistance has been increasing due to the overuse of antibiotics. In some cases, the amoxicillin will not cure the infection, either due to increasing resistance of the strep bacteria or due to increasing resistance of the other bacteria that live in the throat and protect the strep bacteria. In fact, an article in the Journal of Pediatrics Infectious Disease recently reported that in Pittsburgh, 50% of strep bacteria causing sore throats were resistant to another commonly used antibiotic, Zithromax. Therefore, a second or even third course of antibiotics may be prescribed by your doctor to eradicate the disease.
Streptococcal pharyngitis, if not treated, can cause a dangerous condition known as rheumatic fever. In this case, the body’s immune system attack the strep bacteria but mistakenly also attacks the heart valves, which contain proteins similar to the bacteria. This can result in long-term heart disease and sometimes even in death. So it is extremely important to finish the full 10-day course of antibiotics once strep throat is diagnosed.