What is Erythromelalgia (EM) – Types
Erythromelalgia or Erythermalgia or Gerhardt Disease or Mitchell Disease or Weir-Mitchell Disease is a rare and devastating disorder that affects the skin of upper and lower extremities, namely hands or feet or both. It is characterized by erythema (severe redness), episodic or continuous burning pain, elevated skin temperatures of hands and feet and swelling in various body parts. Apart from hands and feet, some other body parts such as ears or nose or face may also be affected.
The name itself describes the condition: Erythros – redness, melos – extremity and algia – pain. Typically, the condition affects both the sides of the body (bilateral), but in some cases only one side of the body is affected (unilateral). The effects of Erythromelalgia may also vary from individual to individual. In some, symptoms develop gradually over a period of several years with mild effects. But, in some cases the onset of symptoms could be sudden and severe.
Types of Gerhardt Disease:
Two different types of classification of this disease exist. First one (primary and secondary) is based on the cause and second (early-onset and late-onset) on the age at which the disease develops.
- Primary – This type of Erythermalgia develops without any underlying cause, spontaneously. It is also referred to as ‘Idiopathic Erythromelalgia.’
- Secondary – This type is associated with myeloproliferative disorders. These disorders are characterized by excessive production of cells by bone marrow as in Essential Thrombocythaemia (increased blood platelets) and Polycythaemia Vera (increased red blood cells). In nearly 85% of people affected by myeloproliferative disorders, Erythromelalgia appears just before the onset of the disorder. It may also develop due to underlying neurological diseases such as peripheral neuropathy, multiple sclerosis etc or autoimmune diseases such as diabetes mellitus, lupus etc or vascular or hematological problems.
- Early-onset Erythromelalgia – This particular type as the name indicates develops below the age of 25 in affected people. It could be running in families and passed on to generations through a family member.
- Late-onset Erythromelalgia – It usually occurs between the age group of 40 and 60.
Information on causes, symptoms and treatment can be found in the next articles.