formocresol and Anaphylaxis

Anaphylactic shock is a real and life threatening medical emergency which is encountered in every field of medicine. The coronary arteries seem to be the primary target of anaphylaxis resulting in the development of Kounis syndrome. Kounis syndrome is a pan-arterial anaphylaxis -associated syndrome affecting patients of any age, involving numerous and continuously increasing causes, with broadening clinical manifestations and covering a wide spectrum of mast cell activation disorders. Recently, Kounis-like syndrome affecting the cerebral arteries was found to be associated with mast cell activation disorders. In anaphylactic shock, the decrease of cerebral blood flow is more than what would be expected from severe arterial hypotension. This is attributed to the early and direct action of anaphylactic mediators on cerebral vessels. While adrenaline is a life saving agent in the treatment of anaphylactic shock, it contains sodium betabisulfite as preservative and should be avoided in sulfite allergic patients. Potential allergens encountered in endodotic practice include formocresol, zinc compounds thiurams, sodium dimethyldithiocarbamade, and mercaptobenzothiazole that might have synergistic action. All these agents together with analgesics, antibiotics, antiseptics, formaldehyde, latex, local anaesthetics and metals used in dental practice, in general, can induce anaphylactic shock. Practitioners should be aware of these consequences. A careful history of previous atopy and reactions is of paramount importance for safe and effective management.

Topics: Anaphylaxis; Brain Injuries; Coronary Vasospasm; Formocresols; Humans; Inflammation Mediators; Mast Cells; Myocardial Infarction; Root Canal Preparation; Syndrome

Formocresol is still used in many parts of the world despite concerns over its toxicity. A case of a 45-year-old women who experienced brain injury after an analyphlactic reaction to formocresol is presented.. During routine root canal treatment, the patient experienced nausea and vomiting after formocresol was used as an antibacterial agent in the pulp chamber. The procedure was discontinued and the symptoms resolved. Four days later, the treatment was continued by a different dentist, and the patient developed anaphylactic shock within 10 min of placement of a formocresol-soaked cotton pellet. She received emergency medical treatment and magnetic resonance imaging (MRI) revealed brain injury characterized by swelling of the gyrus in the cerebral watershed territory of the left parietal-occipital lobe. The patient subsequently made a full recovery after supportive treatment.. A type-I allergic reaction can be induced by formocresol. The reasons for the brain injury are thought to be cerebral hypoxia, which was induced by the anaphylactic shock and/or cerebral parenchymal oedema. All dentists should be aware of the risks involved in the use of formocresol and avoid using materials containing formocresol and related agents.

Topics: Anaphylaxis; Brain Injuries; Female; Formocresols; Humans; Magnetic Resonance Imaging; Middle Aged; Root Canal Therapy