Acrylic resins are widely used in dentistry, especially in orthodontics and prosthetics. Patients: this article reports the case of a leukodermic 33-year-old male who reported discomfort and pain due to an erythematous lesion in the first left premolar after the placement of an acrylic resin temporary restoration. Discussion: The signs and symptoms presented by the patient and his report of visiting the rural countryside generated concern regarding the possible diagnosis, which led to a more invasive biopsy to differentiate allergic inflammation from a paracococcidioid mycosisIncisional. Biopsy revealed a chronic inflammatory process. Conclusion: the pathology was caused by contact with methyl methacrylate-based provisional acrylic resin.