Fibromyalgia in women: somatisation or stress-evoked, sex-dimorphic neuropathic pain?

Somatic symptom disorder is excessive anxiety towards persistent symptoms that do not have an identifiable physical origin. Fibromyalgia is a stress-related illness. The overwhelming majority of fibromyalgia patients seeking medical care are women. Most fibromyalgia sufferers fulfil the somatic symptom disorder diagnostic criteria. The objectives of this article are the following: 1) to examine fibromyalgia and somatic symptom disorder analogy. 2) to discuss stress-evoked neuropathic pain sexual dimorphism, and 3) to propose a neuropathic pathogenesis that may explain how stressed women could develop fibromyalgia. Recent research demonstrates a clear link between fibromyalgia and small fibre neuropathy. Dorsal root ganglia contain the small nerve fibre nuclei. In rodents, physical, chemical, or environmental stressors lead to dorsal root ganglia phenotypic changes and to hyperalgesia. This phenomenon is much more frequent in females. Prolactin, oestrogens, and progesterone alter dorsal root ganglia physiology, establishing abnormal connections between the stress response system and pain pathways. Rather than a mental somatic symptom disorder, fibromyalgia patients may have a stress-induced neuropathic pain syndrome. Sexually dimorphic dorsal root ganglia physiology may explain why it is women who more often develop fibromyalgia. Understanding fibromyalgia as a real stress-evoked neuropathic pain syndrome may lead to more compassionate patient care and may open new avenues for gender-related neuropathic pain investigation.