Background. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a peripheral nervous system disease associated with polyautoimmunity.

Case. We report a previously healthy 13-year old boy who was referred to our outpatient clinic with gait disturbance and distal lower limb weakness that had been increasing for six months. The patient had decreased deep tendon reflexes in the upper extremities and absence in the lower extremities, reduced muscle strength in the distal and proximal lower extremities, muscle atrophy, drop foot, and normal pinprick sensations. The patient was diagnosed with CIDP as a result of clinical findings and electrophysiological studies. Autoimmune diseases and infectious agents were investigated in terms of triggering CIDP. Although there was no clinical sign other than polyneuropathy, he was also diagnosed with Sjögren`s syndrome due to positive antinuclear antibodies and antibodies against Ro52, and with autoimmune sialadenitis. After six months of monthly intravenous immunoglobulin and oral methylprednisolone treatments, the patient was able to dorsiflex his left foot and walk without support.

Conclusions. To our knowledge, our case is the first pediatric case with the coexistence of Sjögren`s syndrome and CIDP. Therefore, we suggest investigating children with CIDP in terms of underlying autoimmune diseases such as Sjögren`s syndrome.

Keywords: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), Sjögren`s syndrome, neuropathy, polyautoimmunity