Pediatric Examination and Board Review (221 page)

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UGGESTED
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Bergstein JM, Riley M, Bang NU. Role of plasminogen-activator inhibitor type 1 in the pathogenesis and outcome of the hemolytic uremic syndrome.
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1992;327:755-759.

Georgaki-Angelaki HN, Steed DB, Chantler C, et al. Renal function following acute renal failure in childhood: a long-term follow-up study.
Kidney Int.
1989;35:84-89.

Gerber A, Karch H, Allerberger F, et al. Clinical course and the role of the Shiga toxin-producing
Escherichia coli
infection in the hemolytic-uremic syndrome in pediatric patients, 1997-2000, in Germany and Austria: a prospective study.
J Infect Dis.
2002;186:493-500.

Neuhaus TJ, Calonder S, Leumann EP. Heterogeneity of atypical hemolytic uremic syndromes.
Arch Dis Child.
1997;76:518-521.

Remuzzi G, Ruggenenti P. The hemolytic uremic syndrome.
Kidney Int.
1995;48:2-19.

Repetto HA. Epidemic hemolytic uremic syndrome in children.
Kidney Int.
1997;52:1708-1719.

Verweyen HM, Karch H, Brandis M, et al. Enterohemorrhagic
Escherichia coli
infections: following transmission routes.
Pediatr Nephrol.
2000;14:73-83.

CASE 128: A 4-YEAR-OLD GIRL WITH A PURPURIC RASH ON THE BUTTOCKS

A 4-year-old girl presents to the emergency department with erythematous maculopapular lesions on the buttocks that extend to the lower extremities and trunk. Initially the lesions blanched on pressure but later became purpuric. As her lower extremities became swollen and painful, her parents brought her to their primary care physician. By the time she was seen by the pediatrician, her chief complaint was severe abdominal pain.

On examination, the temperature was 99.5°F (37.5°C), the pulse was 100 beats/minute, the respiratory rate was 20/minute, and the blood pressure was 110/83 mm Hg. The patient was in moderate distress because of abdominal pain, which was diffuse and intermittent. Palpation of the abdomen revealed a slightly tender sausage-shaped mass in the right upper abdomen. The chest was clear to auscultation, and examination of the heart revealed normal sinus rhythm without a murmur. Examination of the skin over the trunk and buttocks revealed many (10-12) 0.5- to 1-cm purpuric lesions. The patient had mildly swollen ankles and knees with pain on passive movements in all directions.

The urinalysis revealed: specific gravity 1.018, pH 5, protein 3+, 10-20 RBC/HPF, and 5-6 WBC/HPF. The urinary protein-to-creatinine ratio was 1.8. The BUN was 31 mg/dL, the serum creatinine was 0.6 mg/dL, and the Hgb was 11.4 g/dL. The total protein was 6.4 g/dL, the albumin was 3.7 g/dL, and the cholesterol was 151 mg/dL. The C
₃
was 115 mg/dL, the antistreptolysin O antibody less than 200 IU/ mL, and the ANA 1:40.

SELECT THE ONE BEST ANSWER

1.
The first consults to be requested are

(A) intensive care unit (ICU) team

(B) surgery

(C) dermatology

(D) oncology

(E) nephrology for acute dialysis

2.
The renal prognosis in this case

(A) depends on the persistence of hematuria

(B) is excellent because renal function is normal

(C) depends on the magnitude and persistence of proteinuria

(D) is guarded because of the presence of hematuria/ proteinuria

(E) is extremely poor (the patient will likely require a kidney transplant)

3.
Treatment for significant renal involvement in Henoch-Schönlein purpura (HSP) includes

(A) IV and oral corticosteroids

(B) cyclophosphamide

(C) plasmapheresis

(D) IV immune globulin

(E) all of the above

ANSWERS

1.
(B)
HSP is a systemic vasculitis with a prominent cutaneous component. The clinical manifestations include a classic tetrad that can occur in any order and at any time over a period of several days to several weeks: rash, arthralgias, abdominal pain, and renal disease (
Table 128-1
). The disease is selflimited with an excellent long-term prognosis for most children. Long-term outcome usually depends on the degree of renal involvement. GI symptoms are present in most patients with HSP; initial renal involvement is evident in 20-56% of patients. Treatment is usually supportive, but for severe abdominal pain requiring hospitalization or limiting oral intake, oral steroids are usually tried. For joint involvement, nonsteroidal anti-inflammatory drugs (NSAIDs) are often used, providing there is not renal impairment.

Most concerning in this presentation is the sausage shaped-mass in the right upper quadrant (RUQ) that could represent an intussusception. Intussusception, usually ilio-ilial, is a medical emergency that requires a surgical consult before a diagnostic/therapeutic corrective attempt is performed, if possible, by radiology. There are no indications for an ICU admission or acute dialysis.

TABLE 128-1

Abbreviations: E, edema; NR, not reported; NS, nephrotic syndrome

2.
(C)
If renal disease will manifest, it is usually noted within a few days to 4 weeks after the onset of systemic symptoms. The urinalysis in affected patients reveals mild proteinuria with an active urinary sediment characterized by microscopic (or gross) hematuria with red cell and other cellular casts. Most patients have relatively mild disease characterized by asymptomatic hematuria and proteinuria with a normal or only slightly elevated creatinine level. However, more marked findings may occur including the NS, hypertension, and acute renal failure. There is a general but not absolute correlation between the severity of the clinical manifestations and the findings on renal biopsy. Patients with HSP and asymptomatic hematuria usually are not biopsied, but, when done, they only have focal mesangial proliferation. However, if protein excretion is in the nephrotic range, there frequently is crescent formation; thus patients with heavy proteinuria or significant azotemia are usually biopsied. The percent of glomeruli showing crescents seems to be the most important prognostic finding. In general, HSP is characterized by tissue deposition of IgA-containing immune complexes. The pathogenesis of this disorder may be similar to that of IgA nephropathy, which is associated with identical histologic findings in the kidney. The description of the simultaneous occurrence of HSP and IgA nephropathy in twins after an adenoviral infection is further evidence in support of a common pathogenesis. IgA deposition is prominent in both HSP and IgA nephropathy.

3.
(E)
In cases of HSP with severe renal involvement, several therapies have been tried, most frequently increased immunosuppression with corticosteroids or other agents. However, there have been no adequately powered therapeutic trials and because spontaneous recovery is often observed in patients with crescent formation, it remains uncertain whether these regimens are superior to less aggressive therapy or no therapy at all. Similarly, plasmapheresis and IVIG have been tried, but, again, efficacy is uncertain and cases often have concurrent administration of immunosuppression.

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Blanco R, Martinez-Taboada VM, Rodriguez-Valverde V, et al. Henoch-Schönlein purpura in adulthood and childhood: two different expressions of the same syndrome.
Arthritis Rheum.
1997;40:859-864.