Uric Acid Stones Clinical Presentation

Updated: Jun 11, 2018
  • Author: Sahar Fathallah-Shaykh, MD; Chief Editor: Craig B Langman, MD  more...
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Presentation

History

When obtaining the history, attempt to identify factors associated with hyperuricosuria such as the following:

  • Lesch-Nyhan syndrome

  • Familial gout

  • Uricosuric medications

  • Renal insufficiency

  • Malignancy

  • Hemolysis

  • Lead exposure

  • Purine disorders

  • Sarcoidosis

  • Glycogen-storage disease type I

  • Laxative abuse in females with anorexia nervosa [6]

  • Rotavirus-associated gastroenteritis

  • Vesicourethral reflux [7]

Infants with urate crystalluria may have pink-to-orange areas in their diapers after urination. If Serratia marcescens is also present, the diaper may appear red.

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Physical

Renal stones, particularly in the upper urinary tract, cause pain, costovertebral angle tenderness, or both. The manifestations of pain are expressed differently in infants than in teenagers. Hematuria is most often present. Fever, nausea, and vomiting occur. Urinary tract infection may be present.

  • No physical findings are sensitive or specific for uric acid urolithiasis.

  • Children with inherited disorders such as trisomy 21, glycogen-storage disease, or Lesch-Nyhan syndrome may have physical findings consistent with their inherited disease.

  • Children with malignancy may have findings such as lymphadenopathy, hepatosplenomegaly, or paleness secondary to anemia.

  • Tophi (urate deposits) may be present.

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Causes

Uric acid stones are produced when the urinary uric acid concentration is increased secondary to overproduction, increased renal tubular urinary uric acid secretion, decreased renal tubular urinary uric acid reabsorption, decreased urinary water content, or increased hydrogen ion concentration.

Specific causes include the following purine enzyme defects, which lead to overproduction and increased urinary uric acid concentration:

  • HGPRT deficiency

  • PRPP synthetase overactivity

  • Glucose-6-phosphatase deficiency

Other causes include increased nucleotide turnover secondary to cell death.

  • Myeloproliferative and lymphoproliferative disorders

  • Hemolytic anemia

  • Cytotoxic drugs

Other causes include the following:

  • Excessive dietary purine intake producing increased urinary uric acid concentration

  • Hyperuricemia related to rotavirus gastroenteritis likely caused by tissue breakdown in the infected GI tract and dehydration in infants. [3, 2]

  • Decreased glomerular filtration, renal tubular uric acid reabsorption, or both producing increased uric acid concentration in urine (eg, renal failure, acidosis, drugs, lead nephropathy)

  • Dehydration produces decreased urine water content (ie, increased urine solute concentration) and increases urinary uric acid concentration.

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