Acute nephritis, also known as acute glomerulonephritis, is a group of diffuse glomerular inflammatory lesions characterized by acute onset and caused by post-infectious immune reactions resulting from various etiologies. The vast majority of cases are caused by streptococcal infections. This condition is a common pediatric disease, primarily affecting children aged 5 to 10 years; it is rare in children under 2 years of age. Generally, it is more common in boys than in girls. Clinically, the main manifestations include edema, oliguria, hematuria, and hypertension. Most affected children recover after the illness, while only a small number experience a protracted course that progresses to chronic nephritis.
I. Clinical Manifestations
The disease often begins 1 to 4 weeks after tonsillitis, impetigo, or an upper respiratory tract infection. Symptoms may include low-grade fever, dizziness, nausea, vomiting, and loss of appetite.
Edema and Oliguria: Edema typically begins around the eyelids and gradually spreads throughout the body within 1 to 2 days; pitting edema is not prominent upon finger pressure. Urine output decreases with edema, and severe cases may present with anuria.
Hematuria: Nearly all affected children exhibit hematuria at the onset of the disease; approximately 30% present with gross hematuria, while the majority have microscopic hematuria. The color of the hematuria is related to the pH of the urine: if the urine is neutral or weakly alkaline, the hematuria appears bright red or meat-wash-like; if the urine is acidic, it appears tea-colored or ash-gray.
Hypertension: In the first few days after onset, 70% of affected children experience elevated blood pressure, which can reach 120–150/80–110 mmHg. If blood pressure is excessively high or rises too rapidly, precautions must be taken to prevent hypertensive encephalopathy or heart failure. Severe hypertension may manifest as headache, blurred vision, coma, or convulsions.
According to Traditional Chinese Medicine (TCM), this disease is often classified under the TCM concepts of “wind-water” and “yang water” (a type of edema). Its etiology is associated with exposure to external pathogenic factors such as wind-cold, wind-heat, and dampness. Pathologically, it primarily involves the lung, spleen, and kidney.
Wind pathogens rising upward first invade the lungs; when the lungs fail to perform their functions of dispersing and regulating, fluid metabolism is impaired, causing fluid to overflow into the skin and result in edema. Dampness invading internally impairs the spleen’s ability to transport and transform, preventing fluid and dampness from descending; this causes them to accumulate in the skin, leading to edema. The kidneys are the root of all qi in the body and govern the opening and closing of orifices; if kidney qi is deficient, the bladder’s transformative functions are impaired, and fluid accumulates, resulting in edema. Internal invasion by damp-heat, which damages the blood vessels, is the cause of changes in the urine of patients with nephritis; if fluid qi overwhelms the heart, disturbing the clear orifices, or if kidney qi is deficient and the opening and closing functions are impaired, these are the causes of complications in acute nephritis.
II. Treatment of Acute Nephritis
Modern Medical Treatment
(1) Bed Rest: Within the first 1 to 2 weeks of onset, bed rest is required regardless of the severity of the condition; this improves renal blood flow and reduces the incidence of complications. Once edema subsides, gross hematuria disappears, and blood pressure returns to normal, the patient may get out of bed for indoor activities or take walks outdoors. When the erythrocyte sedimentation rate (ESR) returns to normal, the patient may resume school and participate in normal activities.
(2) Diet: Generally, a high-carbohydrate, moderate-fat, salt-free or low-salt diet is prescribed. Protein intake is typically unrestricted; it is limited to 0.5 g/kg/day only in cases of marked oliguria and uremia. However, salt and protein restrictions should not be maintained for too long to avoid impairing growth and development; therefore, a normal diet should be resumed as soon as edema subsides and blood pressure returns to normal.
(3) Antibiotic Therapy: This condition is an immune-mediated disease; antibiotics have little effect on the disease itself but can thoroughly eradicate residual streptococci in the focus of infection. Penicillin or erythromycin may be used; if a throat culture and antibiotic susceptibility testing are performed, an effective antibiotic should be selected.
(4) Symptomatic Treatment
① Diuresis: Administer diuretics, such as oral hydrochlorothiazide, at a dose of 2–3 mg/kg/day.
② Blood Pressure Reduction: For mild elevations in blood pressure, antihypertensive medication is not required; blood pressure can be lowered simply by restricting fluid and salt intake and ensuring bed rest. If blood pressure is excessively high, antihypertensive medication may be administered.
Traditional Chinese Medicine (TCM) Differential Diagnosis and Treatment
(1) For acute nephritis primarily characterized by damp-heat, use the “Fragrant Transformation and Diuretic Formula” (Fanghua Qingli Fang), which has the effects of dispelling turbidity through aromatic properties, clearing heat, and promoting diuresis. Formula ingredients: Agastache, Perilla leaf, Isatis root, Bamboo leaf, Forsythia, and Honeysuckle vine; adjust according to the specific syndrome.
(2) Mainly used for the acute and recovery phases of acute nephritis: clearing heat and detoxifying, promoting blood circulation and resolving stasis, cooling the blood, and stopping bleeding. Use the Acute Nephritis Formula. Ingredients: ① Acute Phase Formula: Motherwort, Sedge Root, Groundsel, Isatis Root, Wild Chrysanthemum, Raw Licorice; ② Recovery Phase Formula: Raw Rehmannia, Greater Thistle, Lesser Thistle, Raw Sanguisorba, Lotus Node, Fried Licorice, Sedge Root. Decoct in water and take orally.
(3) Treatment of all types of acute nephritis in children: Clear heat, promote diuresis, cool the blood, and invigorate blood circulation; Use the Maogen Compound Formula. Ingredients: Maogen, Motherwort, Plantain Herb, Small Thistle. Modify the formula according to the specific syndrome.
For the Wind-Cold type, omit Small Thistle and add Ephedra, Perilla Leaf, and Apricot Kernel;
For the Wind-Heat type, add Honeysuckle, Forsythia, Mulberry Leaf, and Sophora Root;
For the Heat-Predominant-over-Dampness type, add Red Adzuki Beans, Winter Melon Peel, Alisma, and Eclipta;
For the “dampness predominates over heat” pattern, omit Small Thistle and add Poria peel, Areca nut peel, Ginger peel, and Atractylodes;
For hypertension, add Prunella, Achyranthes, and Cassia seeds;
For spleen-kidney deficiency, omit Small Thistle and Plantain Herb, and add Codonopsis, Astragalus, Euryale seed, Rosa laevigata fruit, Chinese yam, Atractylodes, and deer antler powder.
III. Prevention of Acute Nephritis
Patients with upper respiratory tract infections, acute tonsillitis, scarlet fever, and impetigo should receive prompt treatment and be thoroughly cured.
Pay attention to improving children’s nutrition on a daily basis to enhance their overall health.
Ensure children get adequate rest, avoid overexertion, and prevent colds.
After recovery from this disease, patients develop lifelong immunity to this type of streptococcus.