Fatal acute systemic hypersensitivity reaction during haemodialysis.

Haemodialysis (HD)-associated anaphylactic and anaphylactoid reactions are found to be a complex problem, and though they have been well-documented in literature, a number of unexplored aspects remain. Anaphylaxis is a severe, life-threatening, generalized or systemic form of hypersensitivity. The clinical diagnosis is based on case history and physical examination, and includes symptoms of airway obstruction, generalized skin reactions—particularly flushing, itching and urticaria—angio-oedema, cardiovascular symptoms including hypotension and gastrointestinal manifestations. These symptoms result from the action of mast cell and basophil mediators, especially histamine, leukotrienes and platelet-activating factor (PAF) upon shock tissues: blood vessels, mucosal glands, smooth muscles and nerve endings. Mediator release can be triggered by both immunoglobulin E (IgE) and non-IgE factors. As a result, anaphylaxis may be considered to comprise anaphylactic (IgE mediated) or anaphylactoid reactions (non-IgE mediated) [1]. The majority of reported cases have been due to sensitization to ethylene oxide (ETO) [2]. However, a considerable number of publications have focused on other HD substances and materials such as heparins, different dialyser membranes, iron, erythropoietin, polyacrylonitrile AN69 high flux membranes (accumulation of bradykinin) with or without angiotensinconverting enzyme inhibitors (ACEIs), latex, antiseptic or formaldehyde [3]. Many different underlying mechanisms have been postulated. This case report describes a severe clinical syndrome of anaphylaxis during HD, and demonstrates both the complex nature of hypersensitivity reaction to HD and the life-threatening severity of such a reaction.