A pinched nerve, medically known as nerve compression, occurs when surrounding tissues such as bone, cartilage, muscle, or tendons exert pressure on a nerve. While often associated with symptoms like pain, numbness, or tingling sensations, a pinched nerve can also lead to itching. This less common symptom, termed neuropathic itch, stems from the nervous system rather than a skin issue. Understanding this connection can help individuals identify the underlying cause of their itching when typical skin-related explanations are absent.
How Pinched Nerves Cause Itching
The sensation of itching, or pruritus, typically arises from skin irritations. However, when a nerve is compressed or damaged, it can misinterpret signals, leading to neuropathic itch. The nervous system, including sensory nerves, plays a central role in how the brain perceives sensations. Damage to these nerves can cause them to send abnormal signals to the brain, which are then perceived as itching.
This altered sensation is a form of dysesthesia, an unpleasant, abnormal sense of touch, including burning, crawling, or electric shocks, alongside itching. Paresthesia, characterized by tingling, pricking, or “pins and needles” sensations, is a related term. Unlike an itch caused by skin conditions, neuropathic itch originates from within the nervous system, with no external cause like a rash or bug bite. The itch signals are generated by malfunctioning neurons, firing without an external stimulus.
Specific Nerve Compression Conditions
Pinched nerves can cause itching in various parts of the body, depending on the affected nerve. Brachioradial pruritus is an example, characterized by intense itching, stinging, or tingling in the outer forearms, sometimes extending to the shoulders and upper arms. This condition is often linked to irritation or compression of cervical nerves from C5 to C8 levels in the neck. Degenerative changes in the cervical spine, such as herniated discs or bone spurs, can compress these nerve roots, leading to neuropathic itch.
Another condition, notalgia paresthetica, presents as intense itching, burning, or tingling on the inner shoulder blade and spine. This localized itch results from the pinching of nerves in the mid-to-upper back. Similarly, cervical radiculopathy, a pinched nerve in the neck, can cause abnormal sensations including itching, tingling, and numbness in the arms. These examples show how nerve compression in specific locations can manifest as persistent itching.
Identifying Nerve-Related Itching
Distinguishing nerve-related itching from other common causes, such as allergies or skin conditions, is by its unique characteristics. Unlike dermatological itching, which often presents with visible skin changes (rashes, redness, or bumps), nerve-related itching occurs on normal-appearing skin. It may also be accompanied by other neurological symptoms in the same area, such as burning, prickling, numbness, or tingling. These additional sensations can provide clues that the itch has a neurological origin rather than a skin issue.
An indicator of neuropathic itch is its poor response to typical anti-itch treatments like topical creams or oral antihistamines, which target skin inflammation or allergic reactions. The itch can also be severe, persistent, and may worsen with scratching, sometimes leading to secondary skin changes like excoriations or thickened skin. Nerve-related itching may be localized to a specific limb or area, following the affected nerve’s distribution pattern.
Seeking Medical Guidance
Consulting a healthcare professional is important if itching persists for more than a few weeks without improvement, especially if it impacts daily life or sleep. Seek medical guidance if the itching is severe, suddenly appears without explanation, or affects a large part of the body. When itching is accompanied by other concerning symptoms such as severe pain, numbness, tingling, or muscle weakness, it suggests an underlying nerve issue requiring professional evaluation.
A doctor can determine if the itching relates to nerve compression or another medical condition. They can conduct a thorough examination and recommend diagnostic tests to identify the cause. Early diagnosis and management of the underlying nerve problem can help alleviate symptoms and prevent complications.