Myelin-associated glycoprotein-related neuropathy associated with psoriasis: a case report

UNLABELLED INTRODUCTION Psoriasis vulgaris is a common inflammatory disease of the skin, and myelin-associated glycoprotein-related neuropathy is a chronic sensory-predominant polyneuropathy. Although both of these diseases are considered autoimmune diseases, psoriasis with concomitant myelin-associated glycoprotein-related neuropathy is very rare. Here, we report a case of myelin-associated glycoprotein-related neuropathy associated with psoriasis. CASE PRESENTATION A 66-year-old Japanese man, having experienced sternocostoclavicular pain for ten years, was admitted to our hospital because of gait disturbance and numbness of the limbs. Our patient had normal cranial nerve function and normal limb muscle strength. His vibratory and position sense was severely impaired and his touch, temperature and pinprick sensations were mildly disturbed in a glove and stocking distribution. A myelin-associated glycoprotein western blot analysis showed the presence of a 91 to 94kDa band using purified human myelin-associated glycoprotein antigen. His skin lesions were moderately pruritic and Auspitz's sign was positive. Our patient also showed osteitis of his clavicle and manubrium. We diagnosed our patient with myelin-associated glycoprotein-related neuropathy associated with psoriatic arthritis. Five days after intravenous immunoglobulin therapy, his deep sensory impairment began to improve and his sternocostoclavicular pain diminished dramatically. CONCLUSIONS Because myelin-associated glycoprotein-related neuropathy and psoriatic arthritis are both considered autoimmune diseases, we conclude that intravenous immunoglobulin therapy is very effective for patients with an association of these diseases.