There are two forms of Erythromelalgia (EM): primary erythromelalgia/familial, which is inherited, and secondary erythromelalgia.
The disorder may onset gradually, remaining mild over years or decades. But in other cases, the symptoms may begin acutely and rapidly spread, increase in severity and even may become disabling over weeks. Reports show that many people affected with this illness become chronic.
Erythromelalgia may onset gradually, or symptoms may begin acutely and rapidly spread, increase in severity and become disabling over weeks
It has been found that some neuropathies are associated with this illness, with the true underlying cause being unknown. Some researchers have noted similarities between this illness and another blood vessel or vascular condition called Raynaud’s disease. Some other related disorders include Fabry’s disease and RSD/CRPS.
Patients are diagnosed by evaluating the characteristic symptoms and signs of the disease. Patient/family history is helpful, along with specialized tests to exclude other disorders.
Source: U.S Pain Foundation