What is a serious complication associated with untreated impetigo?

Untreated impetigo, particularly when it is caused by group A Streptococcus, can lead to post-streptococcal glomerulonephritis (PSGN), a serious complication that affects the kidneys. PSGN is an immune-mediated condition that generally arises after skin infections, especially those caused by Staphylococcus aureus or Streptococcus pyogenes. When these bacteria invade the skin, the immune response triggered can lead to the formation of antigen-antibody complexes that deposit in the glomeruli of the kidneys. This can result in inflammation and damage to the renal glomeruli, leading to potential kidney dysfunction.

While cellulitis, scarring, and abscess formation can also occur as complications or sequelae of untreated impetigo, they are not as significant as the risk of developing PSGN, which can have long-term implications on kidney health. It is essential to recognize and treat impetigo promptly to prevent these serious complications, particularly PSGN, which can significantly impact the patient's overall health.