CIDP is a rare disease, with prevalence and incidence ranging from 1 to 8.9 per 100,000 population and 0.15 to 1.6 per 100,000 population/year respectively [1], [2]. It is a predominantly male disease, with a male/female sex ratio ranging from 1.3 to 2.8 [1]. The average age of onset is approximately 53 years, ranging from 8 to 80 years [1].

The pathophysiology of CIDP is not fully understood, but both humoral and cellular immunity seem to be involved in its pathogenesis [3], [4]. Unlike Guillain–Barré syndrome (GBS), precessive infection is rare. Several diseases are particularly associated with CIDP: diabetes mellitus, monoclonal gammopathy and hematological malignancies [2], [5], [6], [7], [8], [9]. Rarer associations have been reported, such as solid cancers, connectivitis and granulomatosis, inflammatory bowel disease, membranous glomerulonephritis and infection [10], [11], [12], [13], [14], [15].

Since the first description by Dyck et al. in 1975, the concept of CIDP has evolved considerably [1]. First of all, many variants have been described, widening the clinical spectrum of the disease, with some patients representing a true diagnostic challenge (such as focal CIDP) [2]. Whereas electrodiagnostic studies (EDX) remains mandatory for the diagnosis by showing features of demyelination, many patients do not fulfill demyelination criteria [2], [16]. Therefore, several exams are used to support CIDP diagnosis when EDX are inconclusive. If lumbar puncture and neuromuscular biopsy have been used for decades, the past few years have seen the boom of nerve imaging – MRI and ultrasound –as a helpful tool in the diagnosis, buth many uncertainties remain regarding their sensitivity and specificity, their prognostic role and their impact on therapeutic management. Finally, whereas around 80% of patients improve with immunomodulatory treatments, some patients are refractory to all treatments, and second or third-line strategies are often necessary, without clear guidelines. The discovery of antibodies against the node of Ranvier has been a major breakthrough in patients with IVIg-refractory CIDP patients, with good response to rituximab.

Because CIDP often represents a diagnostic or therapeutic challenge for clinicians, and because several important breakthroughs have been made the past ten years, we elaborated these French recommendations for the management of adult & pediatric CIDP patients. Methodology is detailed in Box 1.