PLASMA CELL GINGIVITIS DUE TO COSMETICS RELATED IODOPROPYNYL BUTYLCARBAMATE (IPBC) ALLERGY IN A TEENAGE FEMALE PATIENT MASKING AS DESQUAMATIVE GINGIVITIS.

Plasma cell gingivitis (PCG) is a rare lesion found on the attached and free gingiva, often extending to the mucogingival junction. Clinically, PCG can appear as sharply delineated erythematous lesions which can be accompanied by edema. We present a case of PCG in a 13 year old female patient which clinically presented as generalized desquamative gingivitis involving the facial aspects of the attached and marginal gingiva that persisted despite substituting to a non flavored dentifrice and failure to elicit any suspected drug or food allergies. Dermatologic patch testing proved positive for Iodopropynyl Butylcarbamate (IPBC), a water based preservative or biocide used in personal care products. Microscopically, there was an intense inflammatory infiltrate in the lamina propria composed predominantly of mature plasma cells. Immunohistochemistry and in situ hybridization showed marked unrestricted cytoplasmic positivity for kappa and lambda light chains. IPBC is used in personal care products comprising lip balms, moisturizers, sunscreens, concealers and body washes due to its effectiveness at preventing fungal growth in topical products. The maximum level for safe use in leave on products is 0.1% but cosmetic products continue to use 10 times more than the safe levels. In the differential spectrum it is pertinent to discriminate erosive lichen planus, cicatricial pemphigoid, acute leukemia, HIV infection clinically; multiple myeloma and plasmacytoma histologically. Our case highlights the importance of patch testing for IPBC allergies in the oral mucosa. IPBC can lead to sensitization and contact dermatitis due to prolonged exposure; as its use in cosmetics continues to rise, and it is difficult to completely eliminate exposure to products containing IPBC especially in the context of teenaged girls and adult female patients.