What are the possible complications of strep throat?
Possible complications of untreated or partially treated strep throat infection are:
- Rheumatic fever
- Otitis media (spread of infection to the middle ear)
- Meningitis (spread of infection to the lining of brain and spinal canal)
- Pneumonia (lung infection)
- Toxic shock syndrome (a rare but severe complication of strep pharyngitis, causing severe widespread infection and organ failure); and/or
- Abscess formation around the tonsils and behind the throat (peri-tonsillar abscess and retro-pharyngeal abscess)
Formation of an abscess behind the throat (retro-pharyngeal abscess) due to untreated or under-treated strep throat infection can lead to severe illness causing pain in throat and neck, difficulty swallowing, and potential respiratory compromise. These abscesses may need to be drained by an ear-nose-throat (ENT) specialist urgently, and hospitalization may be required.
There is also a condition called Pediatric Autoimmune Neuropsychiatric Disorder associated with group A Streptococcus infection (PANDAS). This is a somewhat controversial condition linking group A strep infection in children with possible development and/or exacerbation of obsessive compulsive disorders or tic disorders (Tourette's syndrome) in children.
Acute rheumatic fever (ARF) is a serious complication of strep throat. It is thought that if the strep throat infection is untreated or inadequately treated by antibiotics, the bacteria remain in the tonsils and promote a persistent immune response from the body. Certain strains of the bacteria are more likely than others to cause this response. At times, this ongoing immune response may trigger the immune system to mistakenly attack other organs in the body including the joints (causing inflammation of the joints or arthritis) and the heart valves. The involvement of heart valves can cause damage of the heart valves and potential heart failure.
Treatment with appropriate antibiotics, even if started several days after the resolution of the infection, may prevent acute rheumatic fever. Fortunately, acute rheumatic fever it is now less common than in the pre-antibiotic era.
A similar immune process to acute rheumatic fever may involve the kidneys and result in kidney inflammation called post-streptococcal glomerulonephritis (PSGN). There is unfortunately no evidence that treatment of strep throat will prevent this condition. Children under the age of seven are at the highest risk of developing PSGN after an episode of strep throat. This condition is more common but less ominous than rheumatic fever. It typically resolves spontaneously after a few, weeks and generally does not lead to permanent kidney damage.
Medically reviewed by Robert Cox, MD; American Board of Internal Medicine with subspecialty in Infectious Disease
Medscape. Pharyngitis, Bacterial.
Medscape. Scarlet Fever.