Small fibre neuropathy (SFN) is a condition where damage occurs to small nerve fibres, characterised by severe pain typically beginning in the extremities. It is a type of peripheral neuropathy i.e. affects nerves outside of brain and spinal cord. Whilst it is a lesser known entity therefore requires a greater scientific evidence base, research suggests that SFN occurs more frequently in ME/CFS and certain other conditions associated with dysautonomia than in the general population.
Signs/Symptoms
Symptoms may often be described as painful burning, stabbing, or tingling sensations. Individuals may have reduced pinprick pain sensation but experience increased sensitivity to pain in general (hyperalgesia) and pain from stimuli that would not usually cause pain (allodynia) such as light touch (e.g. bedsheets touching the feet) and increased temperature. Individuals with SFN may also report reduced ability to differentiate between hot and cold temperatures.
There are two types of SFN:
- Length-dependent: Symptoms typically begin in hands and feet (glove and stocking distribution) and advance proximally (closer to centre of body). This is the most common type of SFN.
- Non-length-dependent: Typically has a more patchy diffuse asymmetrical distribution whereby symptoms can occur anywhere in the body including face, scalp and trunk
A complication of the insensitivity to some forms of pain is that skin injury may occur without the individual being aware of this.
Read more about the diagnosis and management of SFN and research linking SFN and ME/CFS
