Pediatric Primary Care (93 page)

2.  Laboratory analysis: formal urinalysis, culture if thought to be infection; urine calcium/creatinine ratio; urine protein/creatinine ratio.

3.  Serum studies: CBC with differential and platelet count, complete metabolic panel, anti-streptolysin enzyme (ASO) or streptozyme, antinuclear antibody (ANA) and C3.

4.  Skin or throat cultures when appropriate.

5.  Sickle cell screen in all African American patients.

6.  Coagulation studies with history of bleeding from other sites.

7.  Cystoscopy: only if persistent gross hematuria.

F.  Differential diagnosis.

1.  Pseudohematuria.

2.  Idiopathic hypercalcemia.

3.  Extrarenal hematuria.

4.  Exercise-induced hematuria.

G.  Treatment.

1.  Systemically ill child with gross hematuria: Admit while being evaluated.

2.  If elevated ASO and low C3 (hypocomplementemia), refer to nephrologist to rule out/treat nephritis.

3.  If abnormal ultrasound, referral to urologist to determine presence of structural anomalies.

4.  With UTIs, refer to urologist and consider VCUG.

5.  Abnormal ANA results, elevated ANA: consult rheumatology, nephrology; commonly associated positive crithidia may indicate lupus erythematosus.

6.  Other blood dyscrasias: consult hematology.

7.  Elevated serum creatinine, hypertension, peripheral edema, abnormal calcium/creatinine ratio, protein/creatinine ratio: refer to nephrologist. Renal biopsy/cystoscopy may be necessary to diagnose.

8.  Urethralgia: hallmarked by blood at end of urinary stream or in underwear, can persist without negative consequence in child for years. Treatment is controversial: Some use antibiotics, but have not been proven effective.

9.  If child develops hypertension or proteinuria, refer to nephrologist. Renal

10.  biopsy may be indicated. 10. If chlamydia or gonorrhea is suspected:

a.  Younger than 9 years of age: erythromycin 50 mg/kg/day qid (max 2 g/day).

b.  9–15 years of age: ceftriaxone 250 mg IM single dose followed by 7 days of doxycycline 200 mg/day bid.

c.  Older than 15 years of age: azithromycin 1 g in 1 dose.

H.  Follow up.

1.  Determined by disease, usually done by appropriate specialist.

2.  Urethralgia without significant symptoms and benign familial hematuria without proteinuria and hypertension: Monitor by checking urine and blood pressure every 6–12 months.

I.  Complications.

1.  Renal failure.

2.  Significant electrolyte imbalance.

3.  Follow up with specialist very important for children with these complications.

J.  Education.

1.  Parents must understand importance of having studies done and follow up with specialists.

2.  If medications prescribed, how and when to give and possible side effects.

3.  Know signs/symptoms of progressive renal disease: edema, hypertension, increasing blood in urine, proteinuria, UTI, lethargy, pallor.

VIII. PROTEINURIA

A.  Etiology.

1.  Renal insufficiency often associated with proteinuria.

2.  Diagnosed by random urinalysis on well-child checkup or associated with serious illness.

3.  Common causes of proteinuria include chronic pyelonephritis, renal scarring, febrile illness, glomerulonephritis, exercise induced, idiopathic, orthostatic, polycystic kidney disease, acute tubular necrosis, cold exposure, congestive heart disease, obstructive uropathy, pregnancy, drug induced, trauma.

B.  Occurrence.

1.  Positive screening by dipstick: approximately 10% of 8- to 15-year olds.

a.  Dipstick finding considered positive if it is 1+ (30 mg/dL). False positives can occur with concentrated urine specimens; if specific gravity is 1.015, dipstick finding for protein needs to be higher than 2+.

2.  If in doubt, look for other symptoms: hypertension, edema, hematuria.

3.  Always best to confirm lower range and asymptomatic results by rechecking/confirming by protein-to-calcium ratio.

C.  Clinical manifestations.

1.  Varies with diagnosis.

2.  Glomerulonephritis presents with hematuria and proteinuria.

a.  ecreased glomerular filtration rate can result in sodium and water retention, oliguria, circulatory overload, edema, hypertension.

b.  Chronic glomerulonephritis results in failure to thrive, slow growth, fatigue.

3.  Postural or orthostatic proteinuria: usually discovered on well-child check.

a.  Usually older than 8 years of age and totally asymptomatic.

b.  Exercise-induced proteinuria is seen after vigorous exercise, resolves with 48 hours rest.

c.  Febrile proteinuria resolves as temperature returns to normal.

4.  Henoch-Schönlein purpura nephritis (a systemic vasculitis) presents with abdominal cramping, purpuric rash, joint pain.

a.  Bloody diarrhea occurs in 50% of patients.

b.  Hemolytic uremic syndrome, systemic lupus erythematosus can also present with purpura, inflammatory bowel.

c.  Known history of renal disease or strong family history of renal compromise.

D.  Physical findings.

1.  Urinalysis shows proteinuria ranging from trace to 4+, microscopic/gross hematuria.

2.  May be associated infection indicated by elevated urine WBC, nitrites.

3.  Blood pressure may be elevated.

4.  Edema (especially periorbital) may be present.

5.  Patient complains of joint pain, stiffness. Joints swollen, inflamed on exam.

6.  Complaints of dysuria or frequency: signs of infection, CVA tenderness, flank pain may indicate obstruction or pyelonephritis.

E.  Diagnostic tests.

1.  In nonacute setting: obtain protein-to-creatinine ratio.

a.  If > 0.2, repeat; if still elevated, obtain 12- or 24-hour urine.

b.  Supine and upright collection obtained to rule out orthostatic proteinuria. Nonpathologic proteinuria associated with posture, fever, or exercise usually yields results < 1 g/24 hours.

c.  Renal ultrasound is normal.

2.  Pathologic proteinuria results from glomerular, tubular disorders of kidney.

a.  Protein-to-creatinine ratio is > 0.2, 24-hour urine results are = 3 g of protein in 24 hours.

b.  Renal ultrasound can show infectious or obstructive nephropathy.

c.  Complete metabolic panel, CBC with differential and platelets, ASO, C3, ANA help sort out the immunologic from the nephrologic causes.

d.  Throat and/or skin cultures can identify post-streptococcal glomerulonephritis.

F.  Differential diagnosis.

1.  See Etiology.

G.  Treatment.

1.  Treatment is dependent on type and severity of proteinuria, obstructive uropathy can be repaired surgically.

2.  Infectious uropathy: Treat with antibiotics.

3.  Associated hypertension: may need short- or long-term treatment.

4.  Urgent nephrology referral with edema and hypertension.

5.  Systemically ill patients require hospitalization to determine cause.

6.  If creatinine-to-protein ratio is > 0.2, refer to nephrology for further evaluation.

H.  Follow up.

1.  Follow up may be lifelong depending on cause.

2.  Recheck asymptomatic proteinuria annually by dipstick analysis and blood pressure: If either is abnormal, referral or additional evaluation needed.

I.  Complications.

1.  Failure to thrive, renal failure, hypertension.