Strep throat is a common bacterial infection affecting the throat and tonsils. It is caused by Group A Streptococcus (GAS) bacteria, also known as Streptococcus pyogenes. This infection is prevalent in school-aged children, though it can affect individuals of any age.
While strep throat symptoms can be uncomfortable, including a sore throat, fever, and swollen glands, the infection is mild. It requires antibiotic treatment. Prompt diagnosis and treatment are necessary to alleviate symptoms, prevent spread, and avert serious health complications.
Acute Rheumatic Fever
Acute Rheumatic Fever (ARF) is a serious inflammatory disease that can develop as a complication of untreated strep throat. This condition arises from an autoimmune response where the body’s immune system, while fighting the strep bacteria, mistakenly attacks its own tissues. This misdirected attack can lead to inflammation and damage in various parts of the body.
ARF can affect the heart, joints, brain, and skin. The most concerning complication is rheumatic heart disease, which involves permanent damage to the heart valves. Symptoms include painful and swollen joints, involuntary jerky movements known as Sydenham’s chorea, a specific rash, and carditis, which is inflammation of the heart muscle.
The onset of ARF is delayed, appearing one to five weeks after the initial strep throat infection. While not everyone with untreated strep throat will develop ARF, the risk exists, especially in children aged 5 to 15. Early and complete antibiotic treatment of strep throat is the primary method to prevent this potentially debilitating disease.
Post-Streptococcal Glomerulonephritis
Post-Streptococcal Glomerulonephritis (PSGN) is a kidney disorder that can occur after an infection with certain strains of Group A Streptococcus, including strep throat or skin infections like impetigo. This condition involves inflammation of the glomeruli, which are the tiny filtering units within the kidneys. When these filters are inflamed, they become less effective at removing waste products and excess fluid from the blood.
The development of PSGN is also linked to an immune response, where immune complexes formed during the strep infection deposit in the kidney filters, causing damage. Symptoms include swelling, particularly in the face, hands, and feet, due to fluid retention, and dark, tea-colored urine resulting from blood in the urine. High blood pressure can also be a symptom.
While many individuals, especially children, recover fully from PSGN, some can experience long-term kidney problems. In rare cases, it can lead to chronic kidney disease or kidney failure. Therefore, recognizing symptoms and seeking medical evaluation after a strep infection is advised, even if the initial strep symptoms were mild or went unnoticed.
PANDAS
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections, or PANDAS, is a condition where a strep infection triggers or significantly worsens certain neuropsychiatric symptoms in children. The theory behind PANDAS suggests that an autoimmune reaction, similar to that seen in rheumatic fever, mistakenly targets parts of the brain. This can lead to a sudden onset or exacerbation of symptoms.
The primary symptoms associated with PANDAS include Obsessive-Compulsive Disorder (OCD) and tic disorders. These symptoms often appear abruptly following a strep infection. Other behavioral changes, such as anxiety, irritability, attention difficulties, and handwriting changes, can also be observed.
The link between the strep infection and the neurological symptoms is believed to be due to antibodies produced by the immune system to fight the strep bacteria. In some susceptible children, these antibodies may cross-react with proteins in the brain, leading to inflammation and neurological dysfunction. Early diagnosis and treatment of strep infections in children are necessary to potentially prevent or mitigate the severity of PANDAS symptoms.
Other Potential Complications
Untreated strep throat can lead to several other localized or systemic complications, though some are less common or less severe than the autoimmune conditions. One such localized complication is a peritonsillar abscess, which is a collection of pus that forms behind the tonsils. This can cause severe throat pain, difficulty swallowing, and fever, often requiring drainage in addition to antibiotics.
Another potential issue is cellulitis, a bacterial skin infection that can occur if the strep bacteria spread from the throat to surrounding tissues. This causes redness, swelling, warmth, and pain in the affected skin area. While less frequent, streptococcal toxic shock syndrome (STSS) represents a severe and rapidly progressing invasive Group A Strep infection. This life-threatening condition involves widespread organ failure and requires immediate medical intervention.