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Chronic pyelonephritis in children
Medical expert of the article
Last reviewed: 07.07.2025
Chronic pyelonephritis in children is a chronic destructive microbial inflammatory process in the tubulointerstitial tissue of the kidneys. Chronic pyelonephritis has a recurrent or latent course.
A distinction is made between chronic primary non-obstructive pyelonephritis and chronic secondary obstructive pyelonephritis.
Chronic primary non-obstructive pyelonephritis is a microbial inflammatory process in the renal parenchyma, when using modern research methods it is not possible to identify the factors and conditions that contribute to the fixation of microorganisms and the development of inflammation in the tubulointerstitial tissue of the kidneys.
Chronic secondary obstructive pyelonephritis is a microbial inflammatory process in renal tissue that develops against the background of developmental anomalies, dysembryogenesis of renal tissue, metabolic disorders (oxaluria, uraturia, phosphaturia, neurogenic dysfunction of the bladder, functional disorders of urodynamics).
In the genesis of primary chronic pyelonephritis, a certain role is played by hereditary factors - antigens HLA-A, and B17 and often antigen combinations A1B5; A1B7; A1B17 (with the highest risk of developing the last two).
[ Symptoms of chronic pyelonephritis in a child
During the period of exacerbation, there are rises in temperature, complaints of pain in the lower back, abdomen, symptoms of intoxication are expressed to one degree or another, dysuric symptoms, urinary syndrome, increased ESR, neutrophilia appear. During the period of remission, fatigue, pale skin, "blueness" under the eyes, asthenia are observed - symptoms of chronic intoxication.
In the case of latent chronic pyelonephritis, there are no clinical manifestations. Pathological changes in urine are detected during preventive examinations, during examinations for visiting a swimming pool, before vaccination, etc. Sometimes attentive parents and doctors who have been monitoring a child for a number of years may note traces of chronic intoxication.
As chronic pyelonephritis develops, patients experience a gradual change in the functions of the renal medulla, and the efficiency of osmotic concentration of urine decreases. A very important diagnostic criterion is a violation of the concentration capacity of the kidneys. It is important to determine the relative density of urine.
It is necessary to conduct a dry-eating test. A dry-eating test lasts 18 hours. From 2 p.m. the patient is asked not to drink anything. In the evening, you can eat cookies, crackers, even fried potatoes. At 8 a.m., urine is collected. After that, the patient drinks as much as he wants. With such a test, the relative density of urine should not be lower than 1.020. If it is lower, this indicates a violation of the concentration ability of the kidneys.
In chronic pyelonephritis, the radiograph reveals: asymmetry in the size of both kidneys; deformation of the renal pelvis and calyces; uneven secretion of contrast agent; decreased thickness of the renal parenchyma compared to the contralateral; significant variations in the thickness of the parenchyma in the same kidney in different areas.
One of the early manifestations of the sclerotic process is the flattening and reduction of the papillae, the lengthening and stretching of the calyces, their pulling to the periphery of the kidneys, and the rounding of the angle at the base of the calyces. The renal-cortical index, the ratio of the area of the renal-pelvic system to the area of the kidney itself, gives an idea of the relationship between the renal-pelvic system and the renal parenchyma. Its value can detect a disproportion between the shrinking renal parenchyma and the expanding renal-pelvic system. The renal-cortical index is normally 60-62%, lower figures indicate chronic pyelonephritis and renal shrinkage. In children with chronic pyelonephritis, the growth rate of the kidneys slows down, which is why it is important to conduct a dynamic X-ray examination.
Radioisotope renography allows to establish unilateral disorders of secretion and excretion, reduction of renal blood flow. Dynamic nephroscintigraphy allows to obtain information about the state of functioning renal parenchyma.
Dynamic computed tomography allows, in chronic pyelonephritis, to determine not only the side of the lesion, but also the degree of impairment of renal vascularization, secretory activity of the tubular epithelium and urodynamics.
The combination of two-dimensional ultrasound and Doppler studies makes it possible to assess the condition of not only the renal parenchyma, but also the blood flow; to assess the peripheral renal vascular resistance. As the process develops in chronic pyelonephritis, arterial hypertension appears.
Due to chronic immune damage, the pathological process in the kidneys steadily progresses, although remissions are possible. In the latent course of chronic pyelonephritis, the urinary syndrome is not stable, it may be normal, in such cases there may be "asymptomatic" bacteriuria. It should also be taken into account that renal dysfunction may persist during the remission period if they are caused by developed nephrosclerosis. Therefore, a sign of exacerbation of chronic pyelonephritis is not the presence of functional disorders, but their increase.
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Treatment of chronic pyelonephritis in children
The regimen includes sufficient sleep, walks in the fresh air, and hygienic measures. During an exacerbation (7-10 days), a dairy-vegetable diet is used with moderate restriction of protein (1.5-2 g/kg of body weight), salt (up to 2-3 g per day). Sufficient fluid intake is recommended - 50% more than the age norm in the form of weak tea, compotes, and juices. It is recommended to take slightly alkaline mineral waters such as Slavyanovskaya, Smirnovskaya at the rate of 2-3 ml/kg of body weight per dose for 20 days, 2 courses per year. Adherence to the regimen of frequent urination (every 2-3 hours, depending on age).
Etiotropic therapy is prescribed taking into account the pathogen culture, it is necessary to change the drugs due to the development of microflora resistance, and after the symptoms of exacerbation subside, long-term maintenance therapy of up to 3-4 months is prescribed for 7-10 days each month. In patients with a high risk of progression, prophylaxis should be carried out for several years.
The presence of vesicoureteral reflux requires increasing the treatment period to 10-12 months. In chronic pyelonephritis, antioxidants, vitamins, drugs that increase the body's reactivity and improve renal blood flow are prescribed.
During the period of stable clinical and laboratory remission, hardening procedures and exercise therapy are carried out.
What is the prognosis for chronic pyelonephritis in children?
Recovery is possible with primary chronic nephritis, while with secondary nephritis, the unfavorable effects include progressive decline in renal function, increasing nephrosclerotic changes and hypertension, and the development of chronic renal failure.