Systemic vasculitis is a predominant clinical symptom in Henoch-Schönlein purpura (HSP), and some studies suggested that decreased blood fibrinolytic activity, as well as blood platelets, is of importance in the development of cutaneous vasculitis. Although patients with HSP have normal blood coagulation, little is known about the fibrinolytic system. On the other hand, it is known that the focus of Σ-aminocaproic acid (EACA) activity in vivo is probably the blood platelet–vessel wall interaction or a vascular component alone. The aim of this study was, therefore, to investigate blood coagulation and fibrinolytic system as well as the effect of hydrocortisone (H) plus EACA therapy (Group I) on plasma antithrombin-III (AT-III), &agr;1-proteinase inhibitor (&agr;1-PI), &agr;2-antiplasmin (&agr;2-A), &agr;2-macroglobulin (&agr;2-M) activity, fibrinogen and plasminogen concentrations in plasma, euglobulin clot lysis time (ELT), and disappearance rate of cutaneous vasculitis in 14 children with HSP aged 7.6 ± 3.1 (SD) years. Ten patients (8.6 ± 2.5 years old) were treated with H alone (Group II), and 8 healthy, age-matched children served as controls. Plasma proteinase inhibitor activity was estimated with the kinetic method using Boehringer chromozyme tests before administration of H (9.2 ± 3.3 mg/kg/d, i.v.) plus EACA (140 ± 52 mg/kg/d, p.o.) for 5.93 ± 2.05 days, and 24 hours after the last dose of EACA, as well as before and after treatment with H alone (8.25 ± 1.74 mg/kg/24 h, i.v.) for 7.1 ± 1.2 days. It was found that patients with HSP had the initial fibrinogen and plasminogen plasma concentrations significantly increased compared with the controls (Group I: 3.93 ± 1.3 g/L and 124 ± 38%; Group II: 4.24 ± 0.89 g/L and 134 ± 42% vs. 2.96 ± 0.34 g/L, and 90 ± 14%, respectively). Also, there was a marked decrease of the initial plasma &agr;2-A activity in Group II compared with the controls (0.69 ± 0.29 vs. 0.94 ± 0.11 IU/mL, respectively, t = 2.33,P< .045). Both treatment regimens significantly improved fibrinolysis, which manifested as a shortening of ELT, but the mean values of this parameter remained within normal range. After treatment with H plus EACA, the skin lesions started to disappear significantly faster compared with the H alone regimen (2.28 ± 0.45 days vs. 4.12 ± 1.05, t = 4.41,P< .0023). In four of six patients receiving H plus EACA therapy, an approximately 20% decrease of systolic and diastolic arterial blood pressure lasting for 5 to 7 hours after administration of EACA was observed. These results may suggest that children with HSP have impaired plasma fibrinolytic activity and that an increased release of plasminogen activator inhibitor-1 (PAI-1) might be, at least in part, responsible for this phenomenon. Concomitant use of H (∼10 mg/kg/d) plus EACA (∼100 mg/kg/d) for a few days opens new therapeutic possibilities in some children with HSP.