Immediate Hypersensitivity Reactions to Paraformaldehyde Used as a Dental Material.

According to actual recommendations, the use of paraformaldehyde as a dental material should be significantly limited; however, it is still used in certain cases. Its use can cause delayed anaphylaxis, which can be life-threatening. We analyzed 157 patients admitted to an allergological clinic between 2017 and 2022 because of a hypersensitivity reaction after dental treatment. Paraformaldehyde was used in 24 of them. Positive specific IgE levels against paraformaldehyde were found in 12 patients, which constituted 50% of the whole group of patients who were treated with paraformaldehyde. Twelve patients had negative results of specific IgE against paraformaldehyde estimation (the PF group). Between the study and control groups, the anaphylactic reaction after paraformaldehyde application was analyzed from many aspects; the level of certainty of anaphylaxis according to Brighton criteria was significantly higher in the PF-positive group than in controls. None of the patients treated with paraformaldehyde as a dental material was informed by a dentist about this risk and symptoms of anaphylaxis. Patients who received paraformaldehyde during dental treatment should be informed of the possibility, symptoms, and treatment of an anaphylactic reaction, which might occur even 24 h after treatment. [ABSTRACT FROM AUTHOR]