Streptococcus pyogenes as the aetiological agent of Henoch–Schönlein purpura
Henoch–Schönlein purpura is a systemic disease mainly affecting school age children. It is characterised by leukocytoclastic small-vessel vasculitis with the deposition of IgA-containing immune complexes in cutaneous, gastrointestinal, articular and renal vessels. Although the cause is still unknown, potential aetiological factors include infectious agents, drugs, exposure to physical factors, allergens or tumour antigens. Streptococcus pyogenes responsible for bacterial pharyngitis is one of the infectious agents that can cause Henoch–Schönlein purpura. The disease is generally mild and self-limiting. Usually, only symptomatic treatment is used. However, renal, gastrointestinal and articular involvement may occur in some cases, which may require intensified treatment. Glucocorticoids are usually used in the case of nephropathy, severe pain and limited mobility of the joints as well as gastrointestinal symptoms. There are also attempts with cyclosporine A, azathioprine, methotrexate, cyclophosphamide, and plasmapheresis. ACE inhibitors are also used to reduce proteinuria and control blood pressure. The paper presents two paediatric cases of Henoch–Schönlein purpura developing within a few weeks following upper respiratory infection. Diagnosis in search of the aetiological factor showed elevated ASO titres and confirmed Streptococcus pyogenes infection in both cases. Regression of symptoms was observed after causal treatment with antibiotic.