Letters to the Editor

Authors


16 November 2008

Dear Editor,

HYPERTENSION IN HENOCH–SCHÖNLEIN PURPURA WITHOUT RENAL INVOLVEMENT

Henoch–Schönlein purpura (HSP) characterised by association of skin rashes, joint involvement, gastrointestinal symptoms and renal involvement, is an acute small-vessel leucocytoclastic vasculitis1. The incidence of HSP varies between 10 and 15 cases per 100 000 a year. It can occur at any age, but is most common in early childhood2. Renal involvement occurs in 30–50% of cases. Microscopic haematuria is the most common finding; proteinuria is associated with haematuria in 60% of patients. Hypertension in patients with HSP is almost associated with renal abnormality. However, the presence of hypertension without evidence of renal involvement is uncommon. We report a new paediatric case of HSP with hypertension without renal abnormalities.

A 12-year-old female presented to our paediatric unit on 14 December 2007 for abdominal pain. She had a history of a rash on her feet 10 days prior to admission. Three days later, she developed a typical palpable purpuric rash on her legs and buttocks, severe intermittent abdominal pain and arthralgia. Diagnosis of HSP was made. She weighed 43 kg and her height was 1.53 m, temperature was at 37.5°C. Physical examination noted a palpable purpuric rash on the buttocks and legs, mild diffuse abdominal tenderness. Her blood pressure measured by auscultation was 150/90 mmHg. The remaining physical examination was normal. Fundoscopy showed middle gastritis. Prior to admission, she received no medications. Laboratory tests, including renal function, serum electrolyte, complete blood count, urine stick testing were normal. Inflammatory markers were slightly increased. Urinalysis showed no blood or protein. On microscopic examination, there were no white blood cells or red blood cells. An autoantibody screen, including rheumatoid factor, serum antinuclear antibody, C3 and C4 complement, and serum immunoglobulin concentrations were all normal. Evolution was marked by recurrence of paroxystic abdominal pain. Intussusception was ruled out by imaging studies. Then, her abdominal pain resolved within 48 h of admission whereas her hypertension persisted. Her blood pressure was controlled with nifedipine 1 mg/kg three times a day. Urine sticks testing, serum creatinine and urea values remained normal throughout her course. A complement evaluation of her hypertension was performed: renal ultrasound with Doppler showed kidneys of normal size, without morphological anomalies, good blood flow through the renal vessels and the adrenal glands were normal. Echocardiography was also normal. Clinical course improved with stabilisation of her blood pressure. Antihypertensive medication was continued for 30 days and then discontinued. After 1 month of discharge, blood pressures were 90/60 mmHg. After 6 months of follow up, child is clinically well with normal blood pressure, urinalyses and renal function.

Occurrence of hypertension in children with HSP without renal involvement is extremely rare. To the best of our knowledge, it has previously been reported in only eight cases in the literature.3–6 Renal involvement in HSP is reported to occur in 15–60% of patients. Henoch–Schönlein nephritis is the cause of end-stage renal failure in 1–3% of cases. Renal manifestations include microscopic or macroscopic haematuria, proteinuria, nephritic or nephrotic syndrome, and rapidly progressive glomerulonephritis. If hypertension occurs, one of these renal abnormalities is almost present. In young children, hypertension is usually secondary.4 The common causes are renal parenchymal disease, renovascular abnormalities and coarctation of the aorta. Endocrinal origin such us pheochromocytoma or Cushing syndrome is rare. Our patient did not have evidence of renal abnormalities either acutely or after 6 months of follow-up. Her hypertension had required medical treatment. Evolution was favourable after resolution of her HSP. We think that our patient's hypertension was associated with her HSP. In the literature, co-occurrence of hypertension and HSP without urinary abnormalities has been reported only in three cases with a favourable outcome.4–6 Since evolution of hypertension was favourable in previously reported cases without renal abnormalities, we propose to defer a full evaluation for other causes of hypertension after resolving other manifestations of HSP. Our patient had only minimal imaging tests with study of renal function and urinalyses.

To conclude, our case shows that occurrence of hypertension during HSP without renal involvement is possible. Report of new cases may clarify pathogeny of hypertension during HSP in the absence of renal involvement.

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