Signs and Symptoms
The first sign of the disease is usually numbness, burning or tingling in the affected areas most often the lower extremities like the feet and toes. These symptoms then travel in an upward trajectory, starting in the longer nerves moving towards the outer nerve endings that are close to the surface of the skin.
The disease usually starts sometime in adolescence to mid adulthood, pain usually starts as a centralized whole body pain consisting of stabbing, tingling, itching, or burning that is more felt in moments of inactivity or nighttime rest.
The pain will then extend into the extremities as the patient ages. One of the strange side effects of SFPN is that while patients will not be able to feel very localized pain in small areas well, they suffer from hyperalgesia and hyperesthesia and will have less capacity to distinguish between hot and cold stimuli even though in some patients pain triggers may be activated by hot or cold sensations.
Along with the primary symptoms of SFPN, patients may also find themselves suffering from heart palpitations, dry eyes and mouth, precipitous drops in blood pressure which can lead to dizzy spells with fainting, blurred vision and abnormal sweating. Some may also experience problems with the bowels and urinary system.
Although SFPN is a disease on its own, it does fall under the general umbrella of peripheral neuropathy as it affects the peripheral nervous system specifically. In most cases of SFPN there is a genetic component involved in SFPN and it’s an autosomal dominant inheritance pattern, but most patients do not develop the disease without a trigger.