Causes of Glomerulonephritis in Children: Understanding the Triggers and Risk Factors
Glomerulonephritis in children is a complex kidney condition that involves inflammation of the glomeruli—the tiny filtering units in the kidneys responsible for removing waste and excess fluids from the blood. This disorder can manifest in various forms, primarily categorized by duration and underlying cause: acute, persistent (or prolonged), and chronic glomerulonephritis. Each type presents unique clinical features and progression patterns, requiring careful diagnosis and management to prevent long-term kidney damage.
Acute Glomerulonephritis: Often Linked to Infections
One of the most common types seen in pediatric patients is acute post-infectious glomerulonephritis, which typically develops after a bacterial or viral infection. The leading culprit is a prior group A beta-hemolytic streptococcal infection—often following strep throat or skin infections like impetigo. This immune-mediated response usually occurs 1–3 weeks after the initial infection, when the body's immune system mistakenly attacks the kidney's filtration system.
In addition to streptococcal causes, other pathogens such as Mycoplasma pneumoniae, certain viruses (including Epstein-Barr virus and cytomegalovirus), and even some parasitic infections have been associated with triggering glomerular inflammation in children. While these cases are less frequent, they highlight the diverse range of infectious agents capable of provoking this condition.
Chronic and Persistent Forms: A Broader Spectrum of Causes
When symptoms last longer than three months, the condition may be classified as persistent or chronic glomerulonephritis. These long-term variants often stem from different etiologies and require more in-depth evaluation. They are generally grouped into three main categories: primary, secondary, and hereditary (genetic) causes.
Primary Glomerulonephritis: No Clear Underlying Disease
This form occurs without an identifiable systemic illness. Although the exact trigger remains unknown, experts believe it results from a combination of genetic predisposition, immune system dysregulation, and environmental influences. Conditions like minimal change disease, focal segmental glomerulosclerosis (FSGS), and IgA nephropathy fall under this category. These disorders lead to symptoms such as proteinuria (excess protein in urine), hematuria (blood in urine), and sometimes nephrotic syndrome in children.
Secondary Glomerulonephritis: Caused by Systemic Illnesses
In contrast, secondary glomerulonephritis arises due to well-established systemic diseases. Among children, some of the most notable include:
- Henoch-Schönlein purpura (HSP) nephritis – an autoimmune condition following upper respiratory infections, marked by skin rash, joint pain, abdominal discomfort, and kidney involvement.
- Lupus nephritis – a complication of systemic lupus erythematosus (SLE), where the immune system attacks multiple organs, including the kidneys.
- Hepatitis B-associated glomerulonephritis – particularly seen in endemic regions, where chronic hepatitis B infection leads to immune complex deposition in the glomeruli.
Early detection and treatment of these underlying conditions are crucial to preserving renal function and improving long-term outcomes.
Hereditary and Genetic Kidney Disorders
A smaller but significant subset of pediatric glomerulonephritis cases stems from inherited genetic mutations. These conditions often run in families and may present early in life with persistent hematuria, proteinuria, or progressive kidney failure. Examples include Alport syndrome, congenital nephrotic syndrome, and thin basement membrane disease.
Children with a family history of kidney disease, hearing loss, or eye abnormalities should undergo thorough genetic screening. Identifying these syndromes early allows for proactive monitoring and personalized care plans that may slow disease progression.
Understanding the root causes of glomerulonephritis in children is essential for accurate diagnosis and effective treatment. Parents and caregivers should remain vigilant about signs such as swelling (especially around the eyes and legs), dark or foamy urine, fatigue, and high blood pressure. Prompt medical evaluation can make a critical difference in protecting a child's kidney health and overall well-being.