Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) takes place when the body’s immune system mistakenly attacks the protective covering (myelin) surrounding the peripheral nerves.

This ongoing immune attack causes inflammation and damage to the myelin sheath, which disrupts the normal flow of electrical signals between the brain, spinal cord, and the rest of the body.

As a result, messages that control movement and sensation become slowed or blocked.

CIDP typically develops gradually over weeks or months, unlike its acute counterpart, Guillain-Barré Syndrome (GBS), which progresses rapidly.

The inflammation leads to persistent weakness, tingling, and numbness in the arms and legs. Over time, people with CIDP may notice increasing fatigue, balance problems, or difficulty walking or performing routine activities.

If left untreated, CIDP can cause lasting nerve damage, but with early diagnosis and treatment—such as corticosteroids, intravenous immunoglobulin (IVIG), or plasma exchange—many patients experience improvement and recovery.

Molecular mimicry theory suggests that, in rare cases, components of a vaccine (such as proteins or antigens) may resemble molecules naturally found in the body’s nervous system.

When the immune system activates to fight what it perceives as a foreign substance, it may mistakenly target these similar-looking molecules in the myelin sheath, the protective covering of peripheral nerves.

This mistaken attack causes chronic inflammation and demyelination, disrupting the normal communication between nerves and muscles.

Over time, this process can lead to the progressive weakness, numbness, and sensory loss that define CIDP.

What CIDP Feels Like:

• Gradual onset of weakness in the arms and legs (often starting in the legs)

• Numbness, tingling, or burning sensations in hands and feet

• Loss of balance or difficulty walking

• Fatigue and reduced reflexes

• Pain or cramping in affected areas

• Symptoms typically worsen over at least eight weeks and may come and go in cycles

Typical treatment for CIDP includes:

• Corticosteroids (like prednisone) to reduce inflammation and suppress immune activity

• IVIG (intravenous immunoglobulin) therapy to neutralize harmful antibodies

• Plasma exchange (plasmapheresis) to remove antibodies from the blood

• Physical and occupational therapy to rebuild strength and maintain mobility

• Long-term management may include immune-modulating medications to prevent relapses

• Affects about 1 to 8 people per 100,000 worldwide

• Men are affected slightly more often than women

• Most common in adults aged 50 and older, though it can occur at any age

• Roughly 80–90% of patients respond to treatment, though some experience relapses or long-term nerve damage