An Allergy-Based Approach to Orofacial Granulomatosis: A Narrative Review

<u><b><i></i></b></u> The relationship between orofacial granulomatous (OFG) conditions and allergy is evolving. Contact allergies are commonly reported, but the impact of allergy avoidance is unclear, and a current review evaluating this literature has not been performed. We identified 46 studies evaluating the impact of allergen avoidance in OFG (33 case reports, 5 case series, 5 single-arm interventional clinical trials, 1 non-randomized uncontrolled trial, and 2 prospective cohort studies). Patch testing was performed in 158 patients, and the most commonly reported allergens were gold (n = 2), mercury (n = 6), cinnamal/cinnamon (n = 27), sorbic acid (n = 7), grass/silver birch/plant-containing products (n = 22), fragrance (n = 5), nickel (n = 7), and benzoic acid (n = 21). When allergen avoidance was trialed, 123/171 (71%) of patients reported some degree of improvement. A validated scoring/grading system for Granulomatous Cheilitis, Melkerrson-Rosenthal syndrome, and OFG has not been developed, so we were unable to formally assess improvement, instead relying on physician- and patient-reported outcomes in addition to oral disease severity score reporting in several studies. Current literature supports both patch testing and a trial of allergen avoidance/elimination diet to improve OFG in those with a positive result. Few controlled studies have been performed to assess this relationship, and more are needed to evaluate the impact of allergen avoidance. If a patient with difficult-to-treat OFG has a positive patch test and exposure to allergens in their diet, we would recommend a trial of allergen avoidance/elimination diet to facilitate a multimodal approach to improving control of this difficult condition.