What's to know about itching in fibromyalgia?
How does fibromyalgia relate to itching?
Itching is a rare symptom that may only affect a very small number of people with fibromyalgia.
Itching is not often mentioned as a symptom or side effect of fibromyalgia because it is relatively rare.
In one study looking at the frequency of skin-related issues in people with fibromyalgia, itching with no identified cause was reported by 3.3 percent of individuals.
Other skin problems that were reported by people with fibromyalgia included:
- Excessive sweating - 32 percent
- Burning sensation of the skin or mucous membranes - 3.4 percent
- Various unusual skin sensations - 1.7 percent
- Skin lesions from repetitive scratching, itchy lumps on the arms and legs, or thickened skin areas that itch - 1.9 percent
- Inflammation of the skin that does not itch - 9.1 percent
People with fibromyalgia are more sensitive to pain, sensation, and touch than those without the disorder. As a result, any of the above skin problems may feel prickly or itchy to someone with fibromyalgia.
Is itching mentioned in fibromyalgia diagnosis criteria?
The American College of Rheumatology provide criteria for diagnosing fibromyalgia.
The criteria advise that pain and symptoms would need to have been felt in the past week in at least 7 out of 19 body areas. The number of areas that pain is felt is scored between 0-19 and referred to as the person's Widespread Pain Index (WPI) score.
After determining the WPI score, the next step is to work out how severe symptoms are with a Symptom Severity (SS) score. In part one of the SS score, levels of fatigue, waking unrefreshed, and changes in thinking must be rated between 0-3, with 0 rated as having no problem and 3 as severe.
In part two of the SS score, other symptoms that have been experienced in the past week should be checked. One of these many symptoms includes itching.
A doctor will calculate the score from the WPI and total SS in order to work out if the person has fibromyalgia. All symptoms would have to have lasted for at least 3 months at a similar level and not be explained by another condition.
The cause of itching for people with fibromyalgia is not clear. However, the following may play a part.
Central nervous system
The central nervous system is made up of the brain, spinal cord, and nerves. The central nervous system communicates information all around the body through a network of nerve cells
Scientists think that people with fibromyalgia experience changes in the way that the central nervous system processes their pain messages. These changes may develop because of abnormal levels of certain chemicals in the brain that signal pain, called neurotransmitters.
Researchers also believe that the pain receptors in the brain can develop a muscle memory of the pain. This can cause them to become more sensitive and overreact to pain signals.
Itching may occur in fibromyalgia due to certain nerve fibers being activated and causing an itching sensation. Itching and pain share a common pathway positioned in the spinal cord. Pain and itchiness also activate the same sensory brain areas. Someone who is sensitive to pain may also be sensitive to itchiness.
Constant itching may set off a "scratch-itch cycle." Initially, scratching relieves the itch, but with constant scratching the skin becomes damaged. This makes the itching worse, so the person scratches more and itches more.
People with fibromyalgia have abnormal levels of the neurotransmitters dopamine, noradrenaline, and serotonin in the brain. Neurotransmitters are chemical messengers that control communication throughout the brain and body.
Research examining serotonin's role in the skin found that abnormal levels of serotonin cause mice to itch. Researchers also found that when serotonin is released in response to pain, certain receptors are activated that cause itchiness.
Scratching the itch causes the release of serotonin as a pain reliever, which activates the receptors again and causes more itching.
Selective serotonin reuptake inhibitors (SSRIs), such as sertraline and fluoxetine, may help to reduce skin itching.
Treatment side effects
Some medications may have side effects that include itching.
Medications that are used to treat fibromyalgia, including pain relievers, antidepressants, and anti-seizure drugs, can sometimes have side effects of itching in certain people. These medications include:
- Acetaminophen - has a rare side effect of skin, rash, hives, or itching
- Ibuprofen - one of the more common side effects is itching skin
- Naproxen sodium - itching is a common side effect
- Tramadol - itching skin is a common side effect
- Duloxetine and milnacipran - burning, crawling, itching, numbness, prickling, "pins and needles," or tingling feelings are less common side effects
- Pregabalin - itching is a rare side effect
If itching is experienced with fibromyalgia medications, people should check with a doctor to ensure that the symptoms are not an allergic reaction. In some cases of itching, the dosage or medication may need to be altered.
Home remedies and medications
There are no guidelines on how to treat itching in fibromyalgia. However, once the cause of an itch is identified, it can be treated.
Reducing pain symptoms can treat itching activated by pain in fibromyalgia. Medications to treat fibromyalgia pain include:
- Pain relievers - over-the-counter acetaminophen, ibuprofen, and naproxen sodium, or prescribed tramadol
- Antidepressants - duloxetine, milnacipran, and amitriptyline
- Anti-seizure drugs - gabapentin and pregabalin
If one of these medications causes itching, a doctor can recommend an alternative dosage or medication.
To treat itching that is caused by the scratch-itch cycle from damaged skin, the following measures may provide relief:
Alongside using a wet compress and avoiding perfumed soaps, moisturizing the affected skin may help to treat an itch.
- Moisturizing the affected skin at least once a day, especially after baths and showers
- Avoiding perfumed soap or moisturizing lotions
- Using cooling creams or gels on the skin
- Using anti-itch creams or lotions in the short-term containing at least 1 percent hydrocortisone or calamine with capsaicin
- Anesthetic skin creams and lotions such as pramoxine may reduce itching
- Avoiding scratching, trim nails, and wear gloves at night
- Applying cool, wet compresses to the affected area
- Taking a lukewarm bath and adding baking soda, uncooked oatmeal, or colloidal oatmeal
- Taking a hot or cold shower
- Minimizing stress through cognitive behavioral therapy (CBT) or relaxation methods such as meditation or yoga
Persistent itching can interfere with sleep, and a lack of sleep could worsen symptoms of fibromyalgia. Continued scratching may also result in infection.
If a person with fibromyalgia is experiencing persistent itching, they should check their symptoms with a doctor.
Itching linked with fibromyalgia is rare. However, it can be an uncomfortable and irritating problem for those who do experience it.
Depending on the cause of the itch, many methods can be used to relieve symptoms, treat itching, and aim to eliminate the cause. While several self-care measures can be applied at home, it is always best to ask the advice of a doctor if someone has fibromyalgia and is also experiencing itching.