Anaphylactic shock during endodontic treatment due to allergy to formaldehyde in a root canal sealant.

A 41-yr-old patient experienced an anaphylactic shock reaction caused by formaldehyde in a root canal sealant during endodontic treatment. The clinical events, positive skin tests, and a high level of immunoglobin E to formalin RAST (class 4) suggest the involvement of immunoglobin E-dependent mechanisms toward formaldehyde. This very infrequent observation in endodontic therapy focuses attention on the different pathological manifestations related to formalin, their mechanisms, and the prevention possibilities in dentistry.

[IgE allergy due to formaldehyde paste during endodontic treatment. Apropos of 4 cases: 2 with anaphylactic shock and 2 with generalized urticaria].

We report 4 cases of allergic reaction to formaldehyde-containing root canal sealant after endodontic care: 2 anaphylactic shocks and 2 local reactions with generalized urticaria. Allergic IgE mediated mechanisms were suggested by the clinical presentation, skin tests and high levels of anti-formaldehyde IgE. These infrequent but potentially severe reactions after canal treatment led us to examine the involved mechanisms, the diagnostic procedure and the possibility of prevention in odontostomatology.

Receiver operating characteristic analysis: a useful method for a comparison of the clinical relevance of two in vitro IgE tests.

Background: The objectives of this study were to demonstrate the usefulness of Receiver Operating Characteristic (ROC) analysis in the definition of a positive threshold in the comparison of two in vitro tests for detecting IgE antibodies and to determine the clinical relevance of specific IgE tests according to the sensitivity and specificity determined by ROC analysis.

Methods: Specific IgE levels were compared with the use of both MATRIX (Abbott Laboratories, Chicago, Ill.) and PHADEZYM (Pharmacia, Uppsala, Sweden) tests in 109 patients: 86 allergic patients and 23 control subjects.