For a long time, itching in fibromyalgia remained on the margins of the clinical story. An uncomfortable symptom, difficult to describe and even more difficult to recognise. Today, however, neuroscientific research is questioning a widespread belief: that itch does not arise from the skin, but from the nervous system. And there’s nothing imaginary about it.
Those who live with fibromyalgia often describe a deep, insistent sensation that does not find relief in the automatic gesture of scratching. It is not a visible skin reaction, there is no obvious redness, nor clear dermatological signs. Yet the annoyance is real, continuous, at times exhausting.
Testimonies collected by associations such as the Fibromyalgia Association UK describe a sensation similar to small insects moving under the skin, a foreign sensation that seems not to belong to the body. It is precisely from here that science began to look more carefully, shifting the focus from the skin to the nervous circuits.
Neuropathic itching, as it is defined, does not have a superficial origin. It is the result of an alteration of the central or peripheral nervous system, the same one involved in chronic pain. It’s not a skin problem, but how the brain interprets and amplifies the signals it receives.
What is neuropathic pruritus and why is it so common in fibromyalgia
In fibromyalgia the nervous system enters a state of central sensitization. It means that normally harmless stimuli are perceived as intense, annoying, sometimes painful. The line between pain, touch, temperature and itching becomes blurred.
According to several studies, the nerves responsible for sensing itching can become hyperactive, sending continuous signals even in the absence of a real stimulus. This happens when nerves are inflamed, compressed or damaged, or when the brain changes the way it filters sensory information.
Dr. Mark Pellegrino, specialist in fibromyalgia, talks about overactive skin receptors and direct involvement of the autonomic nervous system. This causes not only itching, but also sensations of burning, tingling, numbness and those difficult to explain perceptions that many patients know well.
A key role is played by the so-called silent nociceptors, nerve fibers that normally remain inactive. In the presence of inflammation or stress, however, they can “light up” and become hyperexcitable. Research from 2013 showed that over three-quarters of people with fibromyalgia have this type of alteration.
Because pain and itching travel on the same tracks
The link between pain and itching is closer than previously thought. They share common biological mechanisms and similar neural pathways. Not surprisingly, painful stimuli can reduce itching, while some painkillers, particularly opioids, tend to trigger it.
For years, itching has been considered a sort of “lesser relative” of pain. Today this relationship is supported by scientific data. Clinical studies have observed that drugs used for neuropathic pain, such as gabapentin and pregabalin, are also effective in the treatment of chronic itching, even though they were not created with this objective.
Dermatologist Gil Yosipovitch, one of the leading international experts on the topic, describes pain and itching as different sensations that share the same nervous infrastructure. It is the brain that interprets them in a distinct way, determining opposite behaviors: protection in the case of pain, the need to scratch in the case of itching.
The evidence is increasingly solid. Comparative studies have shown that symptoms such as persistent itching, abnormal sweating and tingling are much more common in people with fibromyalgia than in the general population. More recent research indicates that approximately 60% of fibromyalgia patients experience chronic itching, often in association with pain.
Fibromyalgia, stigma and invisible symptoms
Recognizing itching in fibromyalgia as a neurological and not a psychological symptom has profound implications. Fibromyalgia is still often called a “disease of exclusion,” a diagnosis that comes when nothing else can be found. This label helps to make many symptoms invisible, including itching.
The burden of stigma is particularly evident when considering that fibromyalgia primarily affects women. The statistics speak for themselves: between 80 and 90% of patients are female. And women, even today, are more exposed to the risk of having their symptoms minimized or attributed to emotional factors.
According to Yosipovitch, the change comes from medical training that is more attentive to the neuro-immune mechanisms of pain and itching, but also from the development of objective tools, such as clinical questionnaires, physiological markers and imaging techniques capable of showing alterations in the nervous system.
Meanwhile, research is exploring new therapeutic avenues that take into account the shared biology of pain and itching. In addition to the drugs already used for neuropathic pain, non-pharmacological approaches such as vagus nerve stimulation and acupuncture are being studied.
Stress, brain and body
Epidemiological data indicate that psychological stress can worsen both chronic pain and itching. This, however, does not mean that fibromyalgia is “all in the head”. Stress is a biological event in all respects, capable of influencing hormones, the nervous system and the immune response.
Stress increases the sensitivity of nerve pathways involved in pain and itching and can activate immune cells in the skin that release irritants. Recognizing this link means adopting an integrated vision of the body, without slipping into psychological banalization.
Science is still trying to understand why, in conditions of neuropathic pain, the body tends to coexist pain and itching. What is certain today is that both have a solid biological basis. And this, for those living with fibromyalgia, is not a detail.
You might also be interested in:
