Renal Tubular Acidosis In Children – Symptoms & Treatment

Written by Rakhee M • 

Does your child complain of intense pain when he is urinating? Does he exhibit any obvious growth impairments? If you nodded along anxiously, you might want to consult the doctor, as he may be suffering from renal tubular acidosis or RTA. In the meanwhile, read our post below to learn more about Renal Tubular Acidosis symptoms, causes, types and treatments in children.

What Is Renal Tubular Acidosis?

Renal tubular acidosis or RTA is a disorder in which kidneys are unable to extract excess acid from the blood. The acids are flushed from the body through the urine. Any problem with the task makes the blood acidic and causes health problems (1).

It is important for children with RTA to receive prompt treatment for the same. Any delay in treatment may cause poor growth in the child along with other kidney disorders (2).

[ Read: Kidney Stones In Children ]

About Kidney Functions:

All body functions utilize chemical reactions for various tasks. These chemical reactions produce acid. With RTA, acidosis (excessive acid) becomes the norm. Kidneys remove acids in the urine. They also bring bicarbonate (a base) back into the blood. This is the way kidneys maintain a perfect balance of acid and base in the body (3).

This filtration process in the kidneys is carried by nephrons. These nephrons are small filtering units (4). Each nephron has a tiny tube (renal tubule) attached to it, which carries out the filtration process. Due to genetic defects, health problems and use of drugs, renal tubule function can have functional problems. This can cause RTA (5).

Types Of RTA In Children:

RTA can be of different types.

  1. Type 1 Renal Tubular Acidosis or Distal RTA – It is the most commonly-occurring RTA. ‘Distal’ means distance. In this type of distal renal tubular acidosis, the defect in the tube is at a distance from the tubule start point.
  1. Type 2 Renal Tubular Acidosis or Proximal RTA – ‘Proximal’ means near. In proximal renal tubular acidosis  the defect is close to the starting point of tubules.
  1. Type 3 RTA – It is a combination of type 1 and type 2 RTA. It is no longer used for RTA classification.
  1. Type 4 RTA or Hyperkalemic RTA – Here, the defect is in the transportability of the tubules. This interferes with transport of electrolytes (such as potassium, sodium, chloride) in the body via the blood. It can lead to hyperkalemia, which means excessive potassium in the bloodstream. Excess potassium affects heart health (6).

[ Read: Hydronephrosis In Children ]

Causes Of Renal Tubular Acidosis In Children:

Different types of renal tubular acidosis occur due to many reasons.

  • Type 1 can occur due to hereditary factors or use of certain medicines. It can also occur due to autoimmune disorders like lupus or Sjögren’s syndrome; other conditions like sickle cell anemia, urinary tract infections, hyperthyroidism, hyperparathyroidism, renal medullary cystic disease and others. Any disease that causes abnormal levels of calcium in the kidney can cause harm to distal tubule function. Drugs that can cause type 1 RTA are analgesics, amphotericin B and lithium (7).
  • Diseases that can cause type 2 RTA are Fanconi’s syndrome, Lowe syndrome, and Wilson disease. It can also occur due to fructose intolerance (hereditary) and a deficiency of vitamin D. Use of ifosfamide drug can cause type 2 RTA, which is used in chemotherapy (8).
  • Low levels of a hormone known as aldosterone can cause type 4 RTA. It can also occur if kidneys are not able to respond to aldosterone. The function of aldosterone is to help kidneys regulate proper levels of electrolytes in the body. Type 4 can also occur due to diabetes, urinary tract problems, Addison’s disease, kidney transplant rejections and kidney diseases. Use of certain drugs can also cause type 4 RTA. These drugs are angiotensin-converting enzyme inhibitors (for blood pressure), certain immunosuppressive drugs (suppresses the immune system), pentamidine (an antibiotic that treats pneumonia), NSAIDs (anti-inflammatory, for pain) or potassium-sparing diuretics (for the heart) (9).

Symptoms Of Renal Tubular Acidosis In Children:

RTA symptoms may vary for adults and children.

  • Bone pain
  • Kidney stones
  • Irregular heartbeat
  • Weak bones
  • Paralysis
  • Muscle weakness
  • Muscle cramps
  • Dehydration
  • Stunted growth in kids.
  • Rickets (a disorder that can cause skeletal deformities, deformed legs, trouble walking).
  • Confusion
  • Nausea
  • Fatigue
  • Vomiting (10).

If your child experiences pain during urination, needs to urinate frequently, has cloudy or red/brown urine then these could be signs of kidney stones and hence RTA. If your child has kidney stones, he can also experience back pain or lower abdomen pain. If a child has RTA, physical, developmental problems may be present.

Diagnosing RTA In Children:

For the purpose of diagnosing RTA, your doctor may test your blood or urine sample. High levels of acid in the blood and low levels of the same in the urine may indicate RTA.

  • Blood tests can include blood chemistry and arterial blood gas. Blood chemistry is a test that provides full details of chemical balance in the body along with a picture of the body metabolism. Blood gas refers to levels of carbon dioxide and oxygen in the blood. It also helps determine acid levels in the body.
  • Urine tests can be urine pH and urinalysis. The former tests acid levels in the urine. The latter is a more thorough examination of urine and measures some substances and chemicals present in urine.
  • Depending on your child’s individual symptoms, the doctor may conduct additional tests to confirm your RTA diagnosis.

[ Read: Genetic Disorders In Children ]

Treating RTA In Children:

Renal tubular acidosis treatment, depends on the underlying cause of the disease.

  • If your RTA is due to certain drug use, your doctor may change the dose or ask you to stop using it.
  • If any medical condition is causing the RTA, your doctor may begin treatment for the same.
  • Your doctor may prescribe you an alkaline medicine like sodium bicarbonate, which can normalize the acid levels in the blood. For type 2 RTA, you may need to intake bicarbonate in greater quantities than what is required for type 1 RTA treatment.
  • For type 4 RTA, your doctor may restrict your consumption of potassium.
  • If acidosis is mild, adults may not need any treatment. But for children, treatment may be necessary to check growth and impairment problems.

RTA can cause multiple complications. But it is a treatable condition. If you notice any RTA symptoms in your child, immediately consult a doctor. If RTA is present due to genetic reasons, treatment may be for life. But it is still manageable with medicines and other treatment options.

Does your child suffer from any kidney disorders? How do you help him manage the condition? Please share your experience with our readers.

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