Burning legs

Disturbed sensation of extremities (e.g. tingling, numbness, crawling, pain, burning, etc), most commonly of the feet but sometimes spreading more proximally and/or involving the hands, are common reason for referral to neurology. It is often more noticeable at night, disturbing sleep. These symptoms are often referred to as ‘peripheral neuropathy’, but this is a specific diagnosis and only accounts for some of the people affected.

Avoid using the term ‘peripheral neuropathy’ unless it has been confirmed as the cause. Peripheral neuropathy is almost never the likely cause when symptoms are intermittent.

In our experience, “no identifiable cause (idiopathic)” is the most common cause. Sensory symptoms, especially burning/pain, are commonly worse at night or during walking. Causes, in order of frequency, include:

• Idiopathic
• Peripheral neuropathy (most commonly idiopathic axonal neuropathy in over 65)
• Lumbar spinal stenosis and radiculopathy
• Restless Legs Syndrome (RLS). Burning sensation may complicate RLS, so asking about motor restlessness is sensible. Some cases may also involve involuntary movement of toes – “Painful legs and moving toes syndrome”
• Small fibre neuropathy (including related to diabetes or alcohol). This is often not identifiable on nerve conduction studies. It’s therefore a clinical diagnosis, and the management is symptomatic.
• Ill-fitting footwear or skin problems (e.g. tinea)
• Complex regional pain syndrome is a chronic nociplastic pain syndrome which can involve burning and redness, typically after injury
• Erythromelalgia is a poorly understood condition that causes redness of the feet. It can overlap with complex regional pain syndrome

Diagnosis is clinical. Examination is rarely helpful, but look for positive evidence of a neuropathy, e.g. loss of ankle jerks and/or distal motor weakness.

A peripheral neuropathy blood screen is sensible, adding a ferritin if concerns about restless legs syndrome.

Referral is not usually required, but local neurology services will be happy to provide advice if there is uncertainty.

As symptoms often trouble people at night good sleep hygiene is important, such as restricting alcohol/caffeine intake, managing stress, optimising the bedroom environment, etc.

Neuropathic pain drugs only help neuropathic pain (and even then, only in some cases).

There are no drugs that help numbness or tingling although we commonly find that drugs are mistakenly prescribed for these symptoms. If there is pain strongly suggesting a neuropathic cause, then consider the following options:

• Gabapentin
• Pregabalin
• Duloxetine
• Tricyclics

Success is often limited, and these medicines should be continued only if there is a clear and ongoing benefit.