Symposium: nephrologyManagement of Henoch–Schönlein purpura
Section snippets
Pathophysiology
Investigation of patients who develop HSP has revealed a number of abnormalities which may play a role in the disease process. The nature of the abnormalities underlying susceptibility to the development of HSP are poorly understood, but evidence is emerging of a link with other autoinflammatory disorders associated with dysregulated interleukin-1 (IL-1) homeostasis. The 11 members of the IL-1 family of genes include the genes encoding the pro-inflammatory interleukin-1 [beta] (IL-1B) and its
Diagnosis
There is no specific test for HSP and it is therefore a clinical diagnosis. The rash is the main diagnostic feature and important differential diagnoses include meningococcal sepsis and idiopathic thrombocytopenia. In 2005 the vasculitis group of the Paediatric Rheumatology European Society (PRES) proposed new classification criteria for paediatric vasculitides, replacing the American College of Rheumatology (ACR) classification criteria from 1990. However, these proposed modifications were
Acute management
HSP is a multi-system disease as demonstrated by case reports which have described involvement of all organs (see Table 4). However, most children with HSP follow a relatively benign course and do not require hospital admission. Treatment is symptomatic, consisting of simple analgesia for joint or abdominal discomfort. Non-steroidal anti-inflammatory agents can be used for more severe arthralgia. In the past bed rest has been advised, but this is unnecessary and patients should be allowed to be
HSP nephritis
It is the renal manifestations of HSP which are responsible for any long-term morbidity. Inflammation in the kidneys (nephritis) is suggested by the finding of haematuria and/or proteinuria. A small number of patients will develop an aggressive nephritis during their presenting disease, but this is unusual and the progression is usually more insidious. Approximately 2% of patients develop long-term renal problems and for this reason, patients with haematuria or proteinuria need to be kept under
Follow-up
Concern about the possible development of renal complications is the main driver for the follow-up of children after an episode of HSP. The question of which children need follow-up has been addressed by Narchi through an analysis of papers which have studied unselected groups of patients (cohorts not selected on presence or absence of renal involvement). The studies identified included a total of 1133 children. Normal urinalysis was found in 66% of the cases, while haematuria and/or
Long-term management
In children with established renal disease secondary to HSP there are measures which can be taken to slow down its progression, commonly used in other patients with proteinuric chronic kidney disease. Effective treatment of hypertension is a clear therapeutic goal and the aim should be to start treatment if blood pressure is greater than the 90th centile, reducing it to the 50th centile. As well as having similar abnormalities of IgA glycosylation, the renal lesions of HSPN are identical to
Summary
HSP is a clinical diagnosis and investigations are carried out to exclude other pathologies and identify the presence of renal involvement. There is limited data available to guide management of children with HSP, but recent studies indicate that routine administration of steroids is not beneficial. Children with haematuria and/or proteinuria should be kept under review and those with significant proteinuria (early morning urine protein:creatinine ratio persistently greater than 50 mg/mmol),