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Explainer: What Is CIDP?

Learn more about this commonly misdiagnosed disease associated with weakness, numbness and tingling in the arms and legs.

Black and white illustration of nerves firing

Chronic inflammatory demyelinating polyneuropathy – known as CIDP – is a rare neurological disorder that causes inflammation of the nerves.

A functioning immune system keeps someone healthy by fighting off infections. But for those who have CIDP, the immune system mistakenly attacks the nerves and damages the myelin sheath of peripheral nerves. The myelin sheath is a fatty covering that wraps around and protects nerve fibers, according to the U.S. National Institute of Neurological Disorders and Stroke.

See the National Institutes of Health information page about CIDP.

The National Organization for Rare Disorders estimates that CIDP affects five to seven people out of 100,000. It affects men twice as often as women with an average onset age of 50. 

Treatment is available and CSL Behring recently made an announcement about access to CIDP treatment in the United States.

The disorder can be difficult to diagnose. Its symptoms are commonly confused with other conditions, including Lewis-Sumner Syndrome, multifocal motor neuropathy, and diabetic neuropathy, among others.

CIDP could be the cause of tingling or numbness in the toes and fingers that progress to weakness and impaired function in the legs and arms, according to GBS CIDP Foundation International.

Awareness is key, said Lisa Butler, Executive Director of GBS CIDP Foundation International. The organization recently added multilingual resources on CIDP in 17 languages.  

Left untreated CIDP can cause permanent damage to the nerves and in severe cases, resulting in wheelchair dependency.

“The pitfalls in diagnosis go both ways – the missed diagnosis of CIDP, and the diagnosis of CIDP in people who don’t really have CIDP,” said Michael Cartwright, MD, professor of neurology at Wake Forest University, in an article for Clinical Neurology News.

Doctors should base their diagnosis on laboratory imaging and electrodiagnostic tests, in the context of clinical findings such as patient history, to rule out other disorders, Cartwright said. In his experience, 80% of cases involve both sensory and motor dysfunction that slowly progress over more than eight weeks. 

Patient stories are full of challenge and perseverance. Jean-Philippe told the Plasma Protein Therapeutics Association that the diagnosis changed his life. Learn more about his story.

In Canada, CSL Behring and the CIDP patient organization filmed a four-part video series that featured patients talking about different stages in the patient journey – from undiagnosed to management.

Before diagnosis video

Diagnosis video

Treatment video

Ongoing management video