[Incidence of rheumatoid purpura in children and frequency of associated nephropathy in the Loire region]

Epidemiology of immunoglobulin A vasculitis (Henoch-Schönlein): current state of knowledge

PURPOSE OF REVIEW

To review the current knowledge of epidemiological features of immunoglobulin (Ig) A vasculitis (Henoch-Schönlein) and disease etiology.

RECENT FINDINGS

The annual incidence of IgA vasculitis in the population is an estimated 3-26.7/100 000 for children and infants and 0.8-1.8/100 000 for adults. These may be conservative approximations of the true frequency because of skewed case-finding strategies. In children, the marked autumn-winter peak in incidence rates, the frequent occurrence after an upper respiratory tract infection and the short interval between disease onset in index cases and in other family members collectively point to a transmissible infectious process. A subset of adult IgA vasculitis could be related to preceding or concurrent malignancies. Despite several lines of evidence supporting the critical role of an exogenous factor in IgA vasculitis, recent progress has been made in understanding the genetic susceptibility to IgA vasculitis. Recent findings also lessened the suggestion that IgA vasculitis might be triggered by vaccination.

SUMMARY

IgA vasculitis is two to 33 times more common in children than adults and appears to have a strong environmental component, with possibly different risk factors in childhood and adulthood. Support is strengthening for a role of genetics in IgA vasculitis.

[Hepatitis A infection and Henoch-Schonlein purpura: a rare association]

OBSERVATION

A 10-year-old boy presented cholestatic hepatitis A virus infection confirmed by IGM anti-HAV antibody. Three days after admission, he presented a palpable purpuric rash on the declivous regions, arthralgia and abdominal pain. He met all criteria set by the American College of Rheumatology (ACR) for Henoch Schonlein purpura. The evolution was gradually favorable with no renal involvement (recoil of 3 years and half).

CONCLUSION

Henoch Schonlein purpura is an exceptional extra-hepatic manifestation of hepatitis A infection.

[Henoch-Schonlein purpura and renal tuberculosis]

INTRODUCTION

Henoch-Schonlein purpura (HSP) is a small vessel leucocytoclastic vasculitis with IGA deposit. Its little known underlying pathogenic mechanism probably involves an auto-immune reaction triggered-off by various antigens and notably bacterial or viral infectious agents.

OBSERVATION

An HSP associated with renal tuberculosis was observed in a 12 year-old girl. Renal tuberculosis, suspected because of lumbago with aseptic leukocyturia, was confirmed by the presence of Mycobacterium tuberculosis in the urine and the abnormalities found in intravenous urography. One month after initiation of the antituberculosis treatment, an HSP was confirmed by cutaneous biopsy. Evolution was rapidly favourable. Eight years later, the patient had not presented any other episodes of HSP or renal involvement.

DISCUSSION

The association of a tuberculosis with HSP is very rarely reported in children. The underlying pathogenic mechanisms are not yet clear. It can be triggered-off by tuberculosis or antituberculosis treatment. In our patient, the rapid regression of the symptomatology and pursuit of the treatment without incidents argue against the hypothesis of HSP induced by antituberculosis agents.

Schönlein-henoch purpura in children and adults: diagnosis, pathophysiology and management

Schönlein-Henoch syndrome is a form of systemic small-vessel vasculitis, characterised by vascular and/or mesangial immunoglobulin A1 deposits. The main clinical manifestations are vascular purpura, predominating on the lower limbs, and articular, gastrointestinal and renal symptoms. Pulmonary, cardiac, genital and neurological symptoms have also be observed. The syndrome usually affects children, whereas it is rare in adults. The frequency of renal involvement varies between individual studies (from 20 to 100%). Renal manifestations are usually mild and transient, although chronic nephropathies may occur. Overall, an estimated 2% of children with Schönlein-Henoch purpura progress to renal failure and up to 20% of children with nephritis treated in specialised centres require haemodialysis. The renal prognosis appears to be worse in adults. Aetiological investigations are required, as a triggering factor is found in approximately half the patients (e.g. viral, bacterial and parasitic infections, drugs, toxins, systemic diseases and cancer). Dapsone has beneficial effects on cutaneous, gastrointestinal and articular manifestations in adults, especially those with chronic forms. Corticosteroids may be useful for refractory abdominal pain. Methylprednisolone pulse therapy, immunosuppressive drugs (e.g. cyclophosphamide and azathioprine), plasma exchange and polyclonal immunoglobulin therapy are beneficial in very rare life-threatening forms of the disease and in rare instances where renal function is compromised.