Post-Streptococcal Glomerulonephritis: Symptoms, Diagnosis & Treatment

Introduction

Post-streptococcal glomerulonephritis (PSGN) is a rare but serious kidney condition that can develop after infections caused by certain strains of streptococcus bacteria, such as strep throat or impetigo. This condition occurs when the immune system mistakenly attacks the kidneys, leading to inflammation and impaired kidney function. Although PSGN has been recognized for over a century and is less common today due to improved treatment of streptococcal infections, it remains a concern, particularly in children and in areas with limited healthcare access. This article provides a comprehensive overview of PSGN, covering its risk factors, symptoms, diagnostic tests, treatment options, and home care strategies. By understanding PSGN, patients and caregivers can take proactive steps to ensure timely diagnosis and effective treatment.

Definition

Post-streptococcal glomerulonephritis is a kidney disorder that can develop after a streptococcal infection. This article will cover its risk factors, symptoms, diagnostic tests, medications, procedures, and home care strategies to help manage symptoms.

Description of Post-Streptococcal Glomerulonephritis

Post-streptococcal glomerulonephritis (PSGN) is a type of kidney inflammation that occurs after an infection with group A streptococcus bacteria, commonly responsible for strep throat and skin infections like impetigo. PSGN typically develops 1 to 3 weeks after the initial infection, as the immune system’s response to the bacteria inadvertently damages the kidneys. Antibodies produced to fight the infection can form complexes that become trapped in the kidney’s filtering units, called glomeruli, leading to inflammation and reduced kidney function.

PSGN is more common in children, particularly those aged 5 to 12, but can also affect adults. While relatively rare in developed countries, it remains a significant health issue in areas with limited access to antibiotics and healthcare. According to the World Health Organization, PSGN affects approximately 470,000 people worldwide each year, with the highest incidence in low-income regions. Most patients recover fully with appropriate treatment, but in some cases, PSGN can lead to long-term kidney damage or even kidney failure.

Risk Factors for Developing Post-Streptococcal Glomerulonephritis

Lifestyle Risk Factors

Poor hygiene is a significant risk factor for developing PSGN, as it can contribute to the spread of streptococcal infections, particularly skin infections like impetigo. Living in crowded conditions, such as shelters or densely populated areas, also increases the risk of exposure to streptococcal bacteria. Limited access to healthcare can delay the diagnosis and treatment of streptococcal infections, increasing the likelihood of complications like PSGN. Practicing proper hygiene, such as regular handwashing and prompt treatment of infections, can help reduce the risk.

Medical Risk Factors

Individuals who have recently had a streptococcal infection, such as strep throat or impetigo, are at higher risk of developing PSGN, especially if the infection was not treated with antibiotics or if treatment was incomplete. People with weakened immune systems, such as those with chronic illnesses or on immunosuppressive medications, may also be at greater risk, as their bodies may struggle to fight off infections. Additionally, individuals with a history of kidney disease or other kidney-related conditions may be more susceptible to developing PSGN after a streptococcal infection.

Genetic and Age-Related Risk Factors

Children aged 5 to 12 are the most commonly affected group, likely due to the higher incidence of streptococcal infections in school settings where infections spread easily. While PSGN can occur in adults, it is less common and tends to be more severe. There may also be a genetic component, as some studies suggest that individuals with a family history of kidney disease or immune system disorders may be more prone to developing PSGN. However, more research is needed to fully understand the genetic factors involved.

Clinical Manifestations

Hematuria

Hematuria, or blood in the urine, occurs in approximately 90% of PSGN patients and is one of the hallmark symptoms. Hematuria can be gross (visible to the naked eye) or microscopic (detectable only under a microscope). Inflammation in the glomeruli allows red blood cells to leak into the urine, causing hematuria. This symptom is often one of the first signs of PSGN and may persist for several weeks or months as the kidneys heal.

Edema

Edema, or swelling, affects about 85% of PSGN patients, typically around the eyes and in the lower extremities. This swelling occurs because the kidneys are not filtering fluids properly, leading to fluid retention. Edema is often more pronounced in the morning and may improve throughout the day. In severe cases, fluid can accumulate in the lungs, causing shortness of breath.

Hypertension

Hypertension, or high blood pressure, is present in 60-80% of PSGN cases. The kidneys regulate blood pressure by controlling fluid and salt balance. When the glomeruli are inflamed, they cannot perform this function effectively, leading to fluid overload and increased blood pressure. Hypertension in PSGN can range from mild to severe and may require medication to control. If left untreated, it can lead to complications such as heart failure or stroke.

Proteinuria

Proteinuria, or excess protein in the urine, occurs in about 60-80% of PSGN patients. Normally, the kidneys prevent large molecules like proteins from passing into the urine, but inflammation in the glomeruli allows proteins to leak through. Proteinuria can be detected through a simple urine test and may cause the urine to appear foamy. This symptom usually resolves as the kidneys recover.

Fatigue

Fatigue is a non-specific symptom that affects many PSGN patients, though exact percentages are not well-documented. The body’s response to infection, combined with the kidneys’ reduced ability to filter waste, can lead to tiredness and weakness. Fatigue may also be related to anemia, which can occur if the kidneys are not producing enough erythropoietin, a hormone that stimulates red blood cell production. Rest and proper hydration can help alleviate fatigue.

Oliguria

Oliguria, or reduced urine output, is seen in about 50% of PSGN patients. This occurs because the inflamed glomeruli are not able to filter blood efficiently, leading to decreased urine production. Oliguria is often a sign of more severe kidney involvement and may be accompanied by other symptoms like edema and hypertension. In most cases, urine output improves as the kidneys heal, but in rare cases, it can progress to acute kidney injury.

Abdominal Pain

Abdominal pain is reported in about 30% of PSGN patients, particularly in children. The pain is usually mild and may be related to fluid retention or inflammation affecting surrounding organs. In some cases, abdominal pain can be mistaken for other conditions, such as appendicitis, making thorough evaluation important. The pain typically resolves as kidney inflammation improves.

Headache

Headaches affect around 40% of PSGN patients, often due to high blood pressure, which increases pressure in the brain’s blood vessels. In some cases, headaches may also result from dehydration or electrolyte imbalances caused by impaired kidney function. Managing blood pressure and staying hydrated can help alleviate headaches.

Nausea

Nausea occurs in about 20-30% of PSGN patients, often due to the buildup of waste products in the blood (uremia) from reduced kidney function. Nausea may also be a side effect of medications used to treat high blood pressure or fluid retention. In most cases, nausea improves as kidney function returns to normal.

Vomiting

Vomiting is less common than nausea, affecting about 10-20% of PSGN patients. Like nausea, vomiting is usually caused by uremia or medication side effects. Persistent vomiting can lead to dehydration and electrolyte imbalances, worsening kidney function. If vomiting occurs, seek medical advice to manage symptoms and prevent complications.

Diagnostic Evaluation

The diagnosis of post-streptococcal glomerulonephritis (PSGN) is based on clinical symptoms, patient history, and diagnostic tests. A healthcare provider will typically review the patient’s recent history of streptococcal infection, such as strep throat or impetigo, and assess symptoms like hematuria, edema, and hypertension. Diagnostic tests confirm the diagnosis and assess the severity of kidney involvement, helping to rule out other potential causes of glomerulonephritis and guide treatment decisions.

Urinalysis

Urinalysis is a common test used to evaluate the contents of the urine. A urine sample is analyzed for blood, protein, and other substances. A dipstick test is often used for initial screening, followed by microscopic examination if abnormalities are detected. Urinalysis is crucial in diagnosing PSGN because it can reveal hematuria (blood in the urine) and proteinuria (protein in the urine), both key indicators of kidney inflammation.

Results that Indicate PSGN

In PSGN, urinalysis typically shows red blood cells (hematuria) and protein (proteinuria). Red blood cells may appear as “casts” under the microscope, clumps of cells that form in the kidney tubules. The presence of these casts strongly indicates glomerular inflammation. If urinalysis results are normal, it may suggest that the kidneys are not significantly affected, or another condition may be causing the symptoms. Further testing is needed to confirm or rule out PSGN.

Blood Tests

Blood tests assess overall kidney health and detect signs of infection or inflammation. Common tests measure creatinine and blood urea nitrogen (BUN), waste products filtered by the kidneys. Elevated levels of these substances can indicate impaired kidney function. Blood tests may also check for signs of a recent streptococcal infection, such as elevated antistreptolysin O (ASO) titers.

Results that Indicate PSGN

In PSGN, blood tests often show elevated creatinine and BUN levels, indicating impaired kidney function. An elevated ASO titer suggests a recent streptococcal infection, supporting the PSGN diagnosis. If blood test results are normal, it may indicate that the kidneys are functioning properly, and another cause of the symptoms should be considered. Further testing may be necessary to rule out other forms of glomerulonephritis or kidney disease.

Kidney Function Tests

Kidney function tests, such as the glomerular filtration rate (GFR), assess how well the kidneys are filtering blood. These tests help determine the severity of kidney damage in PSGN. GFR is calculated based on factors like age, sex, and blood creatinine levels. A low GFR indicates reduced kidney function, which may require more aggressive treatment to prevent further damage.

Results that Indicate PSGN

A reduced GFR, along with recent streptococcal infection and other PSGN symptoms, suggests significant kidney involvement. If GFR is within the normal range, it may indicate that the kidneys are still functioning adequately, despite other symptoms. Close monitoring is necessary to ensure kidney function does not deteriorate over time.

Antistreptolysin O (ASO) Titer

The ASO titer measures antibodies produced in response to a streptococcal infection. This test is important in diagnosing PSGN because it helps confirm a recent strep infection, the underlying cause of the condition. The test is performed by drawing a blood sample and measuring the concentration of ASO antibodies.

Results that Indicate PSGN

An elevated ASO titer indicates a recent group A streptococcus infection, the most common cause of PSGN. If the ASO titer is elevated along with symptoms like hematuria and edema, it strongly supports the PSGN diagnosis. If the ASO titer is normal, it may suggest the patient did not have a recent streptococcal infection, and other causes of glomerulonephritis should be considered.

Complement Levels

Complement levels, particularly C3, are often measured in patients suspected of having PSGN. The complement system is part of the immune response, and low C3 levels can indicate that the immune system is actively involved in kidney inflammation. This test is performed by drawing a blood sample and measuring complement protein concentrations.

Results that Indicate PSGN

In PSGN, complement levels, especially C3, are typically low during the acute phase of the disease. The immune system consumes complement proteins as part of the inflammatory response in the kidneys. Low C3 levels, combined with other symptoms and test results, can help confirm the PSGN diagnosis. If complement levels are normal, it may suggest that the immune system is not involved, and other causes of kidney inflammation should be explored.

Kidney Biopsy

A kidney biopsy involves taking a small sample of kidney tissue for examination under a microscope. This test is usually reserved for cases where the diagnosis is unclear or if the patient is not responding to treatment. The biopsy provides detailed information about the extent of kidney damage and the specific type of glomerulonephritis present.

Results that Indicate PSGN

In PSGN, a kidney biopsy typically shows inflammation of the glomeruli, with immune deposits visible under special staining techniques. These deposits consist of antibodies and complement proteins, part of the immune response to the streptococcal infection. If the biopsy shows a different pattern of inflammation, it may suggest another form of glomerulonephritis or kidney disease. A biopsy is not always necessary for diagnosis, but it can be helpful in complex cases.

Imaging Studies

Imaging studies, such as ultrasound or CT scans, assess the size and structure of the kidneys. These tests are non-invasive and help rule out other causes of kidney dysfunction, such as kidney stones or tumors. Imaging is not typically required for diagnosing PSGN but may be used if there is concern about other underlying conditions.

Results that Indicate PSGN

In PSGN, imaging studies usually show normal-sized kidneys, although in some cases, the kidneys may appear slightly swollen due to inflammation. If imaging reveals significant abnormalities, such as cysts or tumors, it may suggest another cause of the patient’s symptoms. Imaging is often used in conjunction with other tests to provide a comprehensive evaluation of kidney health.

Electrolyte Panel

An electrolyte panel measures key electrolytes in the blood, such as sodium, potassium, and bicarbonate. These electrolytes are important for maintaining fluid balance and normal kidney function. Electrolyte imbalances can occur in PSGN due to the kidneys’ reduced ability to filter and regulate these substances.

Results that Indicate PSGN

In PSGN, electrolyte imbalances, such as low sodium (hyponatremia) or high potassium (hyperkalemia), may be present. These imbalances can contribute to symptoms like fatigue, muscle weakness, and irregular heart rhythms. If electrolyte levels are normal, it suggests that the kidneys are still able to regulate these substances effectively, but close monitoring is needed to ensure that imbalances do not develop as the disease progresses.

Urine Culture

A urine culture detects bacteria in the urine, helping rule out a urinary tract infection (UTI) as the cause of the patient’s symptoms. This test involves collecting a urine sample and allowing any bacteria present to grow in a laboratory setting. A urine culture is not typically used to diagnose PSGN but may be performed if there is concern about a concurrent infection.

Results that Indicate PSGN

In PSGN, the urine culture is usually negative, meaning no bacteria are present. This is because PSGN is caused by an immune response to a previous streptococcal infection, not by an active infection in the kidneys or urinary tract. If the urine culture is positive, it may indicate a UTI, which would require separate treatment. A negative urine culture helps confirm that the patient’s symptoms are due to PSGN rather than an infection.

What if All Tests are Negative but Symptoms Persist?

If all diagnostic tests come back negative but symptoms of PSGN persist, it is important to follow up with your healthcare provider. In some cases, symptoms may be due to another form of glomerulonephritis or a different kidney condition. Your doctor may recommend additional testing, such as repeat blood work or imaging studies, to further investigate the cause of your symptoms. It is also possible that the symptoms are related to a different, non-kidney-related issue, which would require a different treatment approach.

Treatment Options for Post-Streptococcal Glomerulonephritis

Medications for Post-Streptococcal Glomerulonephritis

Antibiotics

Antibiotics are used to eliminate any remaining streptococcal bacteria in post-streptococcal glomerulonephritis (PSGN). While they don’t directly address kidney inflammation, they play a vital role in preventing further complications from the infection.

Antibiotics are most effective when administered early, especially if the infection is still active. The infection itself typically resolves within a few days to a week, though kidney inflammation may take longer to subside.

Corticosteroids

Corticosteroids help reduce inflammation and suppress the immune system. They are generally reserved for severe cases of PSGN, particularly when significant kidney damage is present or when other treatments have not been effective.

These medications work by calming the immune response, which in turn reduces kidney inflammation. Symptom relief may occur within days to weeks, though long-term use may be necessary in some cases.

Diuretics

Diuretics, commonly known as “water pills,” assist the kidneys in removing excess fluid, which helps reduce swelling (edema) and lower blood pressure.

Diuretics are often prescribed when PSGN patients experience fluid retention, swelling, or high blood pressure. Patients typically notice reduced swelling and improved blood pressure control within a few days of starting treatment.

ACE Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors help relax blood vessels and lower blood pressure, reducing the strain on the kidneys.

These medications are commonly prescribed for PSGN patients who have high blood pressure or protein in their urine. ACE inhibitors are typically used long-term to protect kidney function, with improvements in blood pressure and proteinuria often seen over weeks to months.

Antihypertensives

Antihypertensive medications are used to lower high blood pressure, which is crucial in PSGN to prevent further kidney damage.

These medications are prescribed when blood pressure remains elevated despite other treatments. They may be used in combination with diuretics or ACE inhibitors, with gradual blood pressure reduction helping to protect the kidneys.

Immunosuppressants

Immunosuppressants work by dampening the immune system to prevent it from attacking the kidneys. These medications are reserved for severe or rapidly progressing cases of PSGN.

While not commonly used in mild cases, immunosuppressants can help reduce kidney inflammation and improve function over time. The full effects may take several weeks to become apparent.

Sodium Bicarbonate

Sodium bicarbonate is used to neutralize excess acid in the blood, which can occur in PSGN due to impaired kidney function.

This treatment is typically prescribed when blood tests indicate metabolic acidosis. It helps restore the body’s acid-base balance, with improvements in symptoms such as fatigue and shortness of breath often seen within days.

Calcium Channel Blockers

Calcium channel blockers help relax blood vessels and lower blood pressure. They are used in PSGN patients who have high blood pressure that is difficult to control.

These medications are typically prescribed when other antihypertensives, such as ACE inhibitors, are not sufficient. Patients can expect improved blood pressure control, which helps protect kidney function.

Statins

Statins are used to lower cholesterol levels, which can contribute to kidney damage in some cases of PSGN.

Statins are prescribed for PSGN patients with elevated cholesterol, particularly those at risk for cardiovascular disease. Over weeks to months, statins help reduce cholesterol levels, offering long-term protection for both the heart and kidneys.

Procedures for Severe Post-Streptococcal Glomerulonephritis

While medications are usually sufficient to manage post-streptococcal glomerulonephritis, severe cases may require additional procedures. These can include dialysis to temporarily support kidney function or, in rare cases, a kidney biopsy to assess the extent of damage. Such procedures are reserved for patients with severe or rapidly progressing disease.

Improving Post-Streptococcal Glomerulonephritis and Seeking Medical Help

In addition to medical treatments, several home remedies and lifestyle changes can help manage symptoms and support recovery from PSGN:

1. Rest: Adequate rest is essential for healing from both the infection and inflammation.
2. Hydration: Drinking plenty of fluids supports kidney function and helps flush out toxins.
3. Low-sodium diet: Reducing salt intake helps control blood pressure and minimize fluid retention.
4. Monitoring blood pressure: Regularly checking your blood pressure at home can help detect changes that may require medical attention.
5. Avoiding strenuous activities: Limiting physical exertion prevents further strain on the kidneys.
6. Maintaining a healthy weight: A healthy weight reduces the risk of complications and supports overall kidney health.
7. Regular follow-up with a healthcare provider: Ongoing monitoring ensures the condition is improving and allows for timely adjustments to treatment.
8. Stress management: Techniques such as meditation or deep breathing can support overall health and aid in recovery.
9. Adequate sleep: Getting enough sleep is crucial for the body’s healing process.

If you or a loved one is experiencing symptoms of PSGN, it’s important to seek medical help promptly. Telemedicine offers a convenient way to consult with healthcare providers from home, allowing for timely diagnosis and treatment without the need for in-person visits.

Living with Post-Streptococcal Glomerulonephritis: Tips for Better Quality of Life

Living with PSGN can be challenging, but there are steps you can take to improve your quality of life:

1. Follow your treatment plan closely, including taking medications as prescribed and attending follow-up appointments.
2. Adopt a kidney-friendly diet, which may involve reducing salt, protein, and potassium intake.
3. Stay active with gentle exercises, such as walking or yoga, to maintain overall health without overexerting yourself.
4. Monitor your symptoms and report any changes, such as increased swelling or changes in urine output, to your healthcare provider.
5. Stay informed about your condition and ask questions during medical appointments to better understand your treatment options.

Conclusion

Post-streptococcal glomerulonephritis is a serious condition that affects the kidneys following a streptococcal infection. Early diagnosis and treatment are essential to prevent complications and protect kidney function. With the right combination of medications, lifestyle changes, and regular medical follow-up, most patients can recover fully or manage their symptoms effectively.

If you suspect you may have PSGN or are experiencing symptoms, our telemedicine practice is here to help. Schedule a virtual consultation with one of our primary care providers to receive personalized care and guidance from the comfort of your home.

James Kingsley

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