Fibromyalgia (FM) is a chronic disorder that primarily causes widespread musculoskeletal pain, profound fatigue, and cognitive difficulties often described as “fibro fog.” The condition involves an altered way the brain and spinal cord process pain signals, leading to heightened sensitivity across the body. Many individuals with FM experience chronic itching, known medically as pruritus, which adds another dimension to their discomfort. This persistent, non-dermatological itching is increasingly recognized as a related symptom, pointing toward a deeper involvement of the nervous system.
Is Pruritus a Common Symptom of Fibromyalgia?
Chronic pruritus is a recognized, non-pain symptom reported more frequently in the FM population than in the general public. A comprehensive population-based analysis demonstrated that the rate of pruritus was nearly double in FM patients compared to controls. The prevalence of persistent itching was significantly higher even after ruling out common dermatological conditions like eczema and xerosis. This itch is frequently described as intense, burning, stinging, or a crawling sensation beneath the skin, often occurring without any visible rash. This symptom is chronic and can significantly disrupt sleep patterns, which in turn exacerbates other FM symptoms like fatigue and pain.
The Neurological Basis of Chronic Itching
The root cause of fibromyalgia-related itching lies in the central nervous system’s heightened reactivity, a process termed central sensitization. This phenomenon involves the nervous system amplifying non-painful signals, causing normal skin sensations like light touch to be misinterpreted as intense itch or pain. The sensory pathways for both itch and pain share common neural structures, meaning that an overactive pain processing system can also lead to an overactive itch response.
Research suggests that many FM patients exhibit features of small fiber neuropathy (SFN), which involves dysfunction in the small nerve fibers in the skin. These small peripheral nerves transmit sensory information, including the perception of pain, temperature, and itch. Damage to these fibers can lead to paradoxical sensations, where a reduced number of nerve endings results in a heightened, abnormal response to stimuli.
Imbalances in certain brain chemicals also contribute to this heightened sensitivity. Neurotransmitters like serotonin, dopamine, and noradrenaline help regulate mood, sleep, and sensory processing. Furthermore, increased levels of inflammatory cytokines and elevated opioid receptors in the skin are believed to contribute to chronic neuropathic pruritus.
Identifying and Eliminating Secondary Causes
For individuals with FM, it is important to distinguish between the neuropathic itch stemming from the condition and itching caused by external factors. A thorough evaluation by a healthcare provider can help isolate the cause, ensuring the correct management strategy is pursued.
Itching can often be a side effect of medications commonly prescribed to treat fibromyalgia. Antidepressants such as duloxetine and milnacipran, and anti-seizure drugs like pregabalin and gabapentin, can sometimes cause or worsen skin sensations. Consulting a doctor about potential drug-related side effects is necessary, though dosage changes should only be made under medical guidance.
It is also important to rule out common dermatological conditions. Dry skin, known as xerosis, is common and can be a significant trigger for an already sensitized nervous system. Environmental factors such as harsh soaps, fragranced lotions, and extreme temperature shifts can easily aggravate the skin and provoke an itchy sensation.
Strategies for Managing Fibromyalgia-Related Itching
Management strategies for FM-related pruritus often focus on calming the overactive nerve signals rather than just treating the skin surface. Topical treatments can provide localized relief by numbing the nerve endings in the skin. Over-the-counter anesthetic creams containing lidocaine or prilocaine can temporarily block nerve signals to reduce the itch sensation.
Cooling measures can help temporarily numb the sensory nerves and interrupt the itch-scratch cycle.
- Applying a cold compress or cool cloth to the affected area for brief periods.
- Taking lukewarm baths.
- Using topical products that contain menthol or aloe vera for a soothing, cooling sensation.
Treating the underlying FM symptoms with nerve-modulating medications can sometimes help alleviate the chronic itching as a secondary benefit. Lifestyle adjustments, such as wearing soft, loose-fitting clothing and practicing stress reduction techniques, are also valuable. Managing stress helps calm the nervous system and potentially reduce the intensity of the neuropathic itch.