Dermatological allergies can have different causes. But the most frequent one in dentistry may be associated with the chemical
agents which are used in dentistry. Even though the hypersensitivity to Formalin in children not frequently is reported, but some
of the researches have shown the skin reaction has happened during or after the endodontic treatments. In spite, this is still a
controversy among the researchers and scientists; we present a case of skin reactions with Pulpotec in a dental clinic. To achieve
the result, the patch test was used.