Background Although the prognosis of Henoch-Schönlein purpura (HSP) is usually favorable, relapses are relatively frequent.
Objectives Our aim was to analyze the frequency, type and risk factors for relapses in a large series of unselected patients with HSP.
Methods Retrospective study of 417 patients from a single center, diagnosed with HSP according to the criteria proposed by Michel et al. (J Rheumatol 1992; 19: 721-28).
Relapse was defined as a new outbreak of HSP in a previously asymptomatic patient (at least for one month). Quantitative variables were expressed as mean ± SD or as median (interquartile range), and compared with the Student t-test or the Mann-Whitney U-test, as appropriate. Dichotomous variables were expressed as percentages and compared by using the chi-square test. The variables associated with HSP relapse in the univariate analysis entered into a stepwise multivariate logistic regression. Statistical analysis was performed using SPSS 15.0.
Results 417 patients (240 men/177 women) were studied; median age, 7.5 years (IQR [5.3 to 20.1]). 315 (75.5%) were children or young people (≤20 years) and 102 (24.5%) adults. Clinical manifestations (onset/HSP established,%) were: skin lesions (55.9/100), nephropathy (24/41.2), gastrointestinal involvement (13.7/64.5), joint symptoms (9.1/63.1) and fever (6.2/20.4). Corticosteroids were the most frequently used drugs (35%), followed by NSAIDs (14%), and cytotoxic agents (5%).
After a median follow-up of 12 (IQR [2-38]) months, complete recovery was observed in most cases (n=346; 83.2%) and persistent and usually mild nephropathy, in 32 patients (7.7%).
Relapses occurred in almost one third of the patients (n=133; 31.9%). Clinical manifestations during relapses were: cutaneous (89.6%); abdominal (27.1%); renal (25.9%) and articular (16.8%). The median number of relapses was 2.4 (IQR [1-3]). The main risk factors for the development of HSP relapse in univariate analysis are shown in the TABLE. After multivariate analyses the most powerful predictive factors for relapse were joint manifestations at disease onset, gastrointestinal manifestations during the course of the disease, and corticosteroid treatment at the time of the first episode of HSP (Table).
Conclusions HSP is usually a benign entity but relapses are not uncommon. Patients with articular symptoms at onset or presenting with gastrointestinal manifestations during the course of the disease or those needing corticosteroids to control the initial episode of HSP, are more prone to develop relapses.
Disclosure of Interest None declared