A case of dysgeusia due to mixed connective tissue disease

Mixed connective tissue disease (MCTD) is a collagen disease of unknown origin characterized by the combination of the symptoms similar to systemic lupus erythematosus, systemic sclerosis, dermatomyositis, and positive anti-U1-RNP antibody. We herein report on the case of a 62-year-old female who first presented with left dysgeusia, together with numbness of the left cheek. After an otorhinolaryngological examination she was examined in the neurological department. The neurological examination clearly showed left trigeminal sensory neuropathy in the maxillary and mandibular nerves. Additionally, in this examination Raynaud's phenomenon, swollen hands, and sclerosis of the fingers were also found. The laboratory examination showed leucopenia and positive anti-U1-RNP antibody. These clinical manifestations and laboratory findings are consistent with a diagnosis of MCTD. The trigeminal sensory neuropathy is also associated with MCTD. We suggested that the left dysgeusia and numbness of the left cheek were due to trigeminal sensory neuropathy. The above symptoms were treated, but failed to improve. We suggested that MCTD should be considered in the differential diagnosis when a patient complains of unilateral dysgeusia and numbness of the cheek. To the best our knowledge, in Japan, our case is the first otorhinolaryngological report on dysgeusia due to MCTD.