Peripheral neuropathy and HIV

Peripheral neuropathy is a common condition amongst people living with HIV.

Neuropathy is damage to the nerves. Nerves transmit signals within the brain and spinal cord (the central nervous system or CNS), and extend from the CNS to the muscles, skin, and organs.

The nerves that are outside the CNS are called the peripheral nervous system (PNS). They transmit sensations (such as touch, vibration, and pain) and control movement. They are also important for balance.

Some of the peripheral nerves control body functions over which we have no conscious control, such as blood flow to the organs or the movement of food through the intestines. This is called the autonomic nervous system.

Symptoms

Peripheral neuropathy usually involves damage to the nerves in the feet or, less commonly, the hands, arms, and legs. When nerves are damaged, their signals do not work properly and can misfire. This results in symptoms that can range from mild tingling and numbness through to pain that makes it impossible even to wear a pair of socks. Some people lose strength in their hands, making it difficult to grip anything. Symptoms are usually ‘symmetrical’, in other words, felt equally on both sides of the body.

Peripheral neuropathy commonly affects the longest nerves in our bodies first, which is why it is usually experienced in the extremities, such as the feet or hands. Occasionally the autonomic nervous system can also be affected, causing symptoms such as dizziness, diarrhoea and erectile dysfunction (inability to get or sustain an erection).

People’s experiences of neuropathy will differ in terms of intensity and how much it affects their life. This is because pain is experienced differently by each person and influenced by a range of biological, psychological, and social factors. These include factors such as genetics, stress, and temperature. There’s more information about dealing with pain on another page.

As there are several possible causes of nerve damage, it is very important to tell your doctor if you have any tingling, numbness, or pain in your hands or feet so that the cause can be properly investigated.

Causes of peripheral neuropathy

The different causes of peripheral neuropathy in people living with HIV, and how they cause nerve damage, are not yet fully understood. The risk of neuropathy in people living with HIV appears to increase if they are older, taller, obese, or have had HIV for a long time.

Neuropathy may be caused by inflammation related to HIV itself, some older antiretroviral drugs, or a combination of both. HIV-related neuropathy tends to emerge gradually whereas antiretroviral-related neuropathy usually develops more quickly and can usually be stopped from worsening by changing medication. The risk of HIV-related neuropathy is reduced by prompt diagnosis and treatment of HIV, before the immune system is too damaged (indicated by a low CD4 count).

The antiretroviral drugs most associated with neuropathy are older treatments that were used in the past – in particular, didanosine (ddI, Videx), zalcitabine (ddC, Hivid), and stavudine (d4T, Zerit). The use of these anti-HIV drugs is now avoided as much as possible.

Not all causes of peripheral neuropathy are necessarily linked to having HIV. For example, uncontrolled diabetes is a leading cause of peripheral neuropathy. There are many other health conditions which can also cause peripheral neuropathy, which means that diagnosing the underlying cause can require many different tests.

Neuropathy can also be caused by treatments for other health conditions including some antibiotics and medications used to treat cardiovascular disease, tuberculosis, and cancer.  For example, peripheral neuropathy is a common side effect of vinblastine and vincristine, which are chemotherapy drugs used to treat many types of cancer including Kaposi’s Sarcoma and lymphomas.

If you take more than one of these drugs, the risk of developing neuropathy may be increased. If you have previously had neuropathy caused by something else, you may also be more likely to develop neuropathy from taking one or more of these drugs.

Peripheral neuropathy can be caused by consuming large amounts of alcohol over many years: the best treatment in this case is to stop or significantly reduce your intake of alcohol.

Peripheral neuropathy can also be caused by a shortage of vitamin B12, which can be more likely among people living with HIV who have low CD4 counts. Vegans are also at greater risk because vitamin B12 is only present in meat and dairy products. If medical tests confirm that you have a vitamin B12 deficiency, your doctor may offer supplements of vitamin B by injection (tablets are largely ineffective because vitamin B is poorly absorbed in the gut). Increasing the vitamin B12 content of your diet may also help a little; foods that are rich in the vitamin include fish, kidneys, liver, beef, pork, eggs, and dairy products. Some vegan foods are fortified with vitamin B12 including certain cereals, nutritional yeast, and non-dairy milks. Ask to see a dietitian at your clinic for more advice.

Diagnosis

If you suspect you may have peripheral neuropathy, speak to your GP or HIV doctor so your symptoms can be assessed. This will involve taking a medical history and some basic tests of co-ordination, reflexes, and memory.

They may refer you to a specialist doctor to conduct this assessment or to have further tests. For example, a nerve conduction study tests the electrical function of your nerves and can identify damage in the large fibres of a peripheral nerve. This is done by placing electrodes on your skin which stimulate the nerve and record its response. It may feel a little uncomfortable, but it isn’t usually painful.

In some cases, a more specialised test may be needed to look for damage to smaller nerve fibres. Quantitative Sensory Testing assesses your ability to feel different sensations (such as touch, cold, warmth, or vibration). Sometimes a small piece of skin (about 4mm square) may be taken from your calf under local anaesthetic so the number of nerve fibres in the outer part of your skin (the epidermis) can be counted.

Treatment and management

If you are diagnosed with peripheral neuropathy, your doctor will then attempt to identify the underlying cause. This will usually require a number of blood tests. Treating the underlying cause is the usual approach to managing peripheral neuropathy, but not all underlying causes are treatable.

If you suspect you may have antiretroviral-related neuropathy, speak to your doctor who may recommend stopping or switching treatment or reducing the dose. If you stop or switch your treatment, you may later be able to go back onto a reduced dose of the drugs without the neuropathy returning.

For some people, symptoms of peripheral neuropathy may disappear once the underlying cause is treated. For others, however, the pain may become episodic (flaring up occasionally) or persistent (chronic or long-lasting). It may relate to changes in temperature – very cold weather, for example. The aim of treatment is to help you manage your pain so that you can reduce the symptoms and improve your quality of life.

Speaking to medical practitioners who understand neuropathy and pain science can be very helpful as they can help you to understand the various influences on your pain, including biological, psychological, and social factors, and help you to manage these better. Your GP or clinician may be able to refer you to a pain specialist.  You can also read more about the causes of persistent pain and how it can be managed on our pain page.

Living with peripheral neuropathy can have a substantial impact on your life, and you may feel isolated and depressed. Seeking support is vital to offsetting these feelings and helping you to manage your symptoms. You can join online forums or attend peer support groups where there may be people who are also living with HIV-related neuropathy. You should also explain to your family and friends what you are going through and how they can offer support.

Different people find different things helpful in managing pain:

Patches and creams containing capsaicin. Capsaicin is a substance made from chilli peppers and is used in many topical painkillers. Its pain-stimulating effect appears to temporarily overwhelm the signals that cause chronic pain. Treatment with strong (8%) capsaicin patches can partially relieve symptoms of peripheral neuropathy for several months and can be repeated at regular intervals.

Heat and cold. Temperature can influence your experience of pain and numbness. You may find that soaking your feet in cold water and wearing warm socks in bed can help to reduce pain.

Avoiding tight shoes and socks.

Pain self-management programmes can help improve your quality of life by giving you an active role in managing your pain. They use evidence-based psychological approaches such as acceptance and commitment therapy to support people living with persistent pain to feel more in control of their lives and better able to cope with pain. Ask your doctor for a referral to a specialist pain management service if you think you would benefit from such a programme.

Gentle exercise. If you are experiencing muscle weakness, exercise can help to build your muscle strength. Any exercise is better than none, so its fine to start slowly, set yourself simple goals, and build up your activity gradually.

Your doctor can give you advice on the type and amount of activity that is safe for you. They may refer you to a physiotherapist who can help you with some exercises if you are worried about exercising on your own.

It’s best if you find an exercise you enjoy, and you might find that you are more motivated and enjoy it more in a group.

Medications. Some medications have been found to relieve pain associated with peripheral neuropathy. It is not certain how they work but it is probably by altering the chemicals in your nerves and brain which affect how you feel pain. These drugs include amitriptyline, gabapentin, pregabalin or duloxetine. These drugs can be used to treat depression or epilepsy, but they can also be prescribed specifically for pain relief.

Unlike conventional painkillers, these medications will need to be taken regularly over extended periods to achieve their effect. It is important to recognise that they will not cure the neuropathy and are only prescribed for symptom control. They will never take away 100% of your pain and may have side effects. Your doctor will work with you to find the medication and dose which best suits you and doesn’t give you too many side effects.

Cannabis or morphine-like drugs (opioids) are not recommended for treating neuropathic pain. They can cause serious side effects.

Complementary therapies. Many people find acupuncture, yoga, mindfulness, and breathing exercises help to reduce pain and manage their symptoms.

Further information

The Foundation for Peripheral Neuropathy website has further information, including tips for managing peripheral neuropathy.

The Physiotherapy Pain Association has a number of useful resources for people living with pain, including general information about pain and tips for keeping active.