Allergic contact dermatitis to immobilization mask used in radiation therapy

Thermoplastic masks made of polyester resin are used to immobilize patients receiving radiation therapy. We describe a case of allergic contact dermatitis (ACD) to a thermoplastic mask worn by a child receiving proton beam therapy for treatment of medulloblastoma. ACD to a thermoplastic mask in an adult was first reported in 2018. (J Med Case Rep. 2018;12:181) To our knowledge, ACD to a thermoplastic mask has not been reported previously in the pediatric population.