Allergic contact dermatitis associated with the use of facemask on a patient with a history of atopy.

Allergic contact dermatitis (ACD) is a skin inflammation caused by an allergic reaction after contact with small external substances capable of being absorbed by the skin. There are several studies describing allergic reactions to intraoral orthodontic appliances, especially those containing nickel. Allergic reactions due to extraoral appliances are not as frequent, and there are relatively few studies about them. Extraoral eactions are attributed to metallic, elastic, or textile parts of the extraoral appliances. This article's purpose was to report the appearance of an allergic contact dermatitis reaction in a 9-year, 2-month-old female patient, with a history of atopic dermatitis, after an orthodontic facemask was fitted. Rapid maxillary expansion was also performed with a Hyrax appliance while a facemask was used. Early diagnosis of this pathology is essential in order to achieve a total regression of the reaction. Orthodontists should be aware that ACD can be caused by facemasks in predisposed patients.