A 35-year-old man complains of inability to close his right eye. Examination shows facial nerve weakness of the upper and lower halves of the face. There are no other cranial nerve abnormalities, and the rest of the neurological examination is normal. The patient is afebrile. Examinations of the heart, chest, abdomen, and skin show no additional abnormalities. There is no lymphadenopathy. About 1 month ago the patient was seen by a dermatologist for a bull’s-eye skin rash 2 weeks after returning from a camping trip in upstate New York. Which of the following is the most likely diagnosis?
A. SarcoidosisThis patient’s symptoms and time course are consistent with stage 2 Lyme disease. A few weeks after a camping trip and presumptive exposure to the Ixodes tick, the patient developed a rash consistent with erythema chronicum migrans (stage 1). Secondary neurologic, cardiac, or arthritic symptoms occur weeks to months after the rash. Facial nerve palsy is one of the more common signs of stage 2 Lyme disease; it may be unilateral (as in this case) or bilateral. Stage 3 Lyme disease occurs months to years later and is characterized by recurrent and sometimes destructive oligoarticular arthritis. Sarcoidosis can cause facial palsy, but there are no other signs or symptoms (such as lymphadenopathy) to suggest this disease. Idiopathic Bell palsy would not account for the previous rash or the exposure history. Syphilis always needs to be considered in the same differential with Lyme disease, but the rash described would be atypical, and the neurologic findings of secondary syphilis are usually associated with mild meningeal inflammation. The upper motor neuron involvement of lacunar infarct would spare the upper forehead.