Unilateral Facial Swelling as the Inaugural Sign of Anti-NPX2 Dermatomyositis: A Diagnostic Challenge in Oral Medicine.

A 41-year-old female patient in apparent good health presented to the dental emergency department with a 6-week history of painless, nonpruritic left facial swelling, and dotted with purplish patches. She had consulted different physicians and dentists and received several ineffective treatments. After ruling out an oral cause, standard blood tests were initially prescribed. They showed an isolated elevation of creatine phosphokinase (CPK). Muscular weakness of the left arm and leg, pain on mobilization of the left thigh, and erythematous plaques on the left body then appeared. Infectious, granulomatous, and autoimmune diseases were investigated. Magnetic resonance imaging (MRI) showed diffuse muscle infiltration, suggestive of myositis. Myositis-specific dot immunoassay identified antinuclear matrix protein 2 (NXP2) autoantibodies, enabling the diagnosis of dermatomyositis. The inaugural orofacial manifestations of dermatomyositis can be confused with pathologies of dental cause, such as cellulitis. In the absence of local warning signs, oral health professionals must consider a systemic etiology and rapidly refer the patient to avoid patient wandering.