Influence of age on Henoch Schonlein purpura
Authors: Robert G Lahita
Journal: The Lancet (1997)

There are different forms of vasculitis, depending on size of vessel and suspected inciting factors such as drugs or infection. The diagnosis is difficult unless there are obvious signs such as purpura or biopsy evidence. Commonly the diagnosis is made despite signs that are only suggestive, to justify immunosuppressive therapy. Equally common is missing the diagnosis. An unusual vasculitic disease is anaphylactoid purpura, or hypersensitivity vasculitis, commonly called Henoch Schonlein purpura (HSP).1Michel BA Hunder GG Bloch DA Calabrese LH Hypersensitivity vasculitis and Henoch Schonlein purpura: a comparison between the two disorders.J Rheum. 1992; 19: 721-728PubMed Google Scholar Unlike most vasculitides, this one is usually self limited, though occasionally progression to death occurs. It is found in children and adults and is likely if the following tetrad is present: abdominal pains, purpura, arthritis, and renal disease. The hallmark of the disease, IgA deposition in the vascular wall of affected or apparently unaffected skin or in the mesangium of the kidney, strengthens the diagnosis even though it is not an official criterion of the Henoch-Schönlein classification.2Mills JA Michel BA Bloch DA et al.The American College of Rheumatology 1990 criterial for classification of Henoch-Schonlein purpura.Arthr Rheum. 1990; 33: 1114-1121Crossref PubMed Scopus (762) Google Scholar Because of the self-limited nature, therapy is usually unnecessary for the uncomplicated case but is recommended for patients with complications such as severe crescentic glomerulonephritis. Even then, the value of therapy is unclear since the renal lesions are usually non-reversible and renal transplants eventually become affected and unresponsive to immunosuppressive drugs. Recently two retrospective studies of HSP, one selecting patients on the basis of skin lesions and the other selecting patients from a pool of patients with small-vessel vasculitis, have produced more data on the influence of age on the disease. The 57 patients in the study by E Tancrede-Bohin and colleagues3Tancrede-Bohin E Ochonisky S Vignon-Pennamen M Flaheul B Morel P Rybojad M Henoch-Schonlein purpura in adult patients.Arch Dermatology. 1997; 133: 438-442Crossref PubMed Google Scholar were aged over 15 years and had cutaneous IgA deposits and purpura but no IgA in the basement membranes of skin-biopsy lesions, and no thrombocytopenia. 23% had IgA glomerulonephritis, 26% urine abnormalities, 33% joint disease, and 19% gastrointestinal complaints. IgA glomerulonephritis was associated with purpura above the waist, an association known in adults. Overall a high percentage (25–49%) of these patients had renal disease, but the researchers did not stratify renal disease by age. The patients with renal disease did not differ from those without in sex, prevalence of bullous or necrotic lesions of the skin, or gastrointestinal or joint involvement. These findings differ from what is known in children, in whom renal involvement is associated with severity of skin lesions and gastrointestinal symptoms. In the paper by R Blanco and colleagues4Blanco R Martinez-Taboada VM Rodriguez-Valverde V Garcia-Fuentes M Gonzalez-Gay MA Henoch-Schonlein purpura in adulthood and childhood.Arthr Rheum. 1997; 40: 859-864Crossref PubMed Scopus (348) Google Scholar the 46 patients aged above 20 were compared with the 116 below 20. There were differences both at the onset of disease and later. In adults abdominal pain, fever, and joint pain were less prevalent but renal disease was commoner at presentation. The higher prevalence of renal disease was the only one of these differences that remained during the course of the disease. Adults also had a raised erythrocyte sedimentation rate. In this study the adults were treated more aggressively than the children with cytotoxic agents and steroids. The majority of adults (89%) and children (94%) recovered. All of these comparisons of so many variables create much confusion in an area already unclear. The cause of HSP is unknown, the presentation and hallmark of the disease are strange, and the clinical course is largely one of reversibility except in a few patients. Occasionally remission occurs with pregnancy and hormone therapy, perhaps the result of sex-hormone influences on IgA and subsequently neutrophil functions.5Merrill J Lahita RG Henoch-Schonlein purpura remitting in pregnancy and during sex steroid therapy.Br J Rheumatol. 1994; 33: 586-588Crossref PubMed Scopus (26) Google Scholar However, in general, adults do not respond as well as children to treatment. The Blanco data resemble those from a previous American College of Rheumatology (ACR) paper2Mills JA Michel BA Bloch DA et al.The American College of Rheumatology 1990 criterial for classification of Henoch-Schonlein purpura.Arthr Rheum. 1990; 33: 1114-1121Crossref PubMed Scopus (762) Google Scholar that were used to establish the earlier diagnostic criteria. The only difference is that the ACR series included more adults who were on medicines that have been linked with the disease.3Tancrede-Bohin E Ochonisky S Vignon-Pennamen M Flaheul B Morel P Rybojad M Henoch-Schonlein purpura in adult patients.Arch Dermatology. 1997; 133: 438-442Crossref PubMed Google Scholar However, no medicine has been conclusively linked to HSP. Other plausible causes of HSP include viral infections. A familial tendency has been reported6Escudero A Lucas E Vidal JB et al.Drug related Henoch Schonlein purpura.Allegol Immunopathol (Madr). 1996; 24: 22-24PubMed Google Scholar and occasionally remission occurs with pregnancy and hormone therapy, the possible result of sex-hormone influences on IgA and subsequently neutrophil function.7Berthoux FC Gagne A Sabatier JC HLA-Bw35 and mesangial IgA glomerulonephritis.N Engl J Med. 1978; 298: 1034-1035PubMed Google Scholar All aspects of HSP remain puzzling. The events that lead to the vasculitides revolve round autoimmunity. Although no alterations of known self antigens have been identified in HSP, antigenic mimicry by a drug or infectious agent might play a part in the pathogenesis, via a type II reaction (antibody to matrix or cell surface). The age-related organ severity (skin in children, kidneys in adults) is unexplained. Moreover the self-limited nature of the illness itself is also perplexing, as is the selective deposition of IgA isotype in tissues such as skin and kidneys. The unpredictability of who will progress to renal failure despite treatment is especially vexing.