Severe manifestation of plasma cell mucositis in a patient with autism spectrum disorder: A unique overlap illustrating challenges with diagnosis and management.

Plasma cell mucositis (PCM) is a rare inflammatory condition affecting the oral tissues, often triggered by allergens or inflammation. Autism spectrum disorder (ASD), a neurodevelopmental condition, poses unique challenges in oral care and hygiene due to behavioral and sensory issues. These conditions have not previously been reported in concert but may share risk factors including through the development of inflammation. We present a case of severe PCM in a 23-year-old male with ASD, illustrating diagnostic complexities and management strategies. The patient presented with widespread and severe lesions, raising the possibility of underlying causes. After multiple interventions, including topical steroids and trigger avoidance, the patient achieved near-complete resolution of the oral lesions. Immunohistochemical and serological investigations suggested an underlying monoclonal gammopathy, warranting hematological evaluation. Our case shows how PCM and ASD can affect each other, highlighting the importance of understanding how these conditions interact, and the need for tailored approaches to oral health in this population. Further research is needed to elucidate any pathophysiological or risk-based link between ASD and inflammatory oral conditions and to refine management strategies for PCM in patients with neurodevelopmental disorders.