Fibromyalgia is a complex, chronic disorder characterized primarily by widespread musculoskeletal pain, but it often involves a host of other debilitating symptoms. People with the condition frequently experience fatigue, sleep disturbances, and cognitive difficulties. A less-publicized but common symptom reported by patients is chronic itching, medically termed pruritus, which can significantly impact quality of life. This persistent, non-pain sensation is now being recognized as a genuine manifestation of the underlying neurological changes associated with fibromyalgia.
Understanding the Link Between Fibromyalgia and Chronic Itching
Fibromyalgia patients frequently report chronic or recurrent itching (pruritus) that is not caused by a typical skin condition. This form of pruritus is often described as neurogenic, meaning it originates from the nervous system rather than from a rash or external irritant. It is sometimes called “fibro-itch” due to its association with the disorder.
The sensation is typically intense and can manifest as a stinging, burning, or even a deep, aching feeling beneath the skin. Patients often describe it as a crawling or “pins and needles” feeling. Unlike common allergic itching, this neurogenic pruritus often does not lead to a visible rash, and scratching usually fails to provide relief, sometimes even intensifying the sensation.
The itching often becomes chronic, lasting for more than six weeks, and can be intermittent or persistent. This symptom is thought to stem from the same nervous system hypersensitivity that lowers the threshold for pain signals. Research suggests that chronic pruritus is significantly more prevalent in individuals with fibromyalgia compared to those without the condition.
Neurological Basis for Pruritus in Fibromyalgia
The underlying mechanism for fibromyalgia-related itching is largely attributed to a state of heightened responsiveness in the central nervous system known as central sensitization. This condition causes the nerves in the brain and spinal cord to process and amplify normal sensory input, including non-pain signals like touch and itch. The result is a dramatically lowered threshold for discomfort, making the skin exquisitely sensitive.
This sensory dysregulation is also linked to the function of small nerve fibers, which are responsible for transmitting pain, temperature, and itch signals from the skin to the spinal cord. A subset of fibromyalgia patients show evidence of small fiber neuropathy (SFN), a condition involving damage or loss of these small nerve fibers. Such damage can cause the remaining nerves to fire improperly or spontaneously, sending dysregulated itch signals to the brain.
Furthermore, the altered levels of certain neurotransmitters appear to play a role in this sensory experience. Imbalances in chemicals like serotonin, which is involved in regulating mood, sleep, and pain, can affect how the body processes sensory input. Research suggests that the pathways for pain and itch share common neural circuits, meaning that a system sensitized to pain is also more likely to be sensitive to itch. This dysfunction involves silent nociceptors—nerve receptors normally activated only by inflammation—which become hyperactive in fibromyalgia, contributing to the persistent itch sensation.
Ruling Out Other Causes of Itching
Since persistent itching is a non-specific symptom, it can be caused by many conditions unrelated to fibromyalgia. A medical professional, such as a dermatologist, should evaluate any persistent or severe pruritus to exclude common dermatological issues. Conditions like eczema, psoriasis, or simple dry skin (xerosis) must be ruled out, especially if the itching is accompanied by a visible rash, hives, or blistering.
It is also necessary to investigate systemic diseases that can cause chronic itching as a secondary symptom. These include issues with the liver, kidneys, or thyroid. A thorough check of current medications is also important, as some drugs commonly prescribed for pain, depression, or sleep can have itching as a side effect.
The defining feature of fibromyalgia-related pruritus is often the absence of a primary skin lesion, meaning the skin looks normal despite the intense sensation. However, if the itching is severe enough to cause broken skin, open sores, or signs of infection from scratching, a medical evaluation is immediately warranted. Tracking the timing and location of the itching can provide helpful information to determine the precise cause.
Strategies for Managing Fibromyalgia-Related Pruritus
Effective management of neurogenic pruritus focuses on calming the hypersensitive nervous system and soothing the skin.
Non-Pharmacological Relief
Non-pharmacological approaches are often the first line of defense and include simple changes to daily routines:
- Applying a cold compress or a cool, refrigerated moisturizer to temporarily numb the nerves and interrupt the itch cycle.
- Using gentle, fragrance-free moisturizing creams regularly to prevent skin dryness.
- Avoiding harsh soaps, hot baths, and tight clothing made of irritating fabrics.
- Opting instead for soft, breathable materials like cotton.
- Practicing stress reduction techniques, such as mindfulness or meditation, as emotional stress can intensify nervous system overactivity.
Pharmacological Treatments
Pharmacological management often uses the same medications effective for treating the underlying pain of fibromyalgia. Antiseizure medications like gabapentin or pregabalin work by calming overactive nerve signals, which can help reduce the intensity of both pain and itch. Certain antidepressants, such as Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs), may also be used because they modulate neurotransmitters involved in sensory processing. Topical treatments containing lidocaine, which acts as a local anesthetic, or mild hydrocortisone cream can also be used to provide temporary, localized relief by blocking nerve signals in the skin.