Final answer:
Post-streptococcal glomerulonephritis presents with symptoms including blood and excessive protein in urine, increased blood pressure, and edema, particularly of the face, hands, and feet, following a recent strep throat or skin infection caused by Streptococcus pyogenes.
Step-by-step explanation:
Clinical Presentation of Post-Streptococcal Glomerulonephritis
Post-streptococcal glomerulonephritis (PSGN) is a form of acute glomerulonephritis that typically arises after an infection with Streptococcus pyogenes, which can cause strep throat or skin infections. PSGN manifests within 6-10 days following pharyngitis and up to 21 days after a skin infection. The hallmark clinical presentation includes hematuria (blood in urine), proteinuria (excess protein in urine), hypertension (increased blood pressure), and oedema (fluid retention leading to swelling), particularly in the face, hands, and feet. This condition is a result of immune complexes formed between the bacterial antigens and the host antibodies depositing in the glomeruli of the kidneys, inducing inflammation and damage.
Additional signs may include acute-phase proteins indicating inflammation, and in severe cases, there can be evidence of renal damage. The condition follows an immune-mediated mechanism, potentially involving molecular mimicry between streptococcal antigens and kidney tissues. This results in an autoimmune response contributing to glomerular damage.
It is important to distinguish PSGN from other causes of glomerulonephritis such as anti-glomerular basement membrane disease, Wegener's granulomatosis, or acute lupus nephritis with systemic lupus erythematosus. Similarly, a distinction should be made from pyelonephritis, which affects the renal pelvis and parenchyma, presenting with symptoms like fever, chills, nausea, and lower back pain.