Erythromelalgia
Erythromelalgia (EM) is a rare condition characterized by episodes of burning pain, warmth, swelling and redness in parts of the body, particularly the hands and feet. This condition may occur spontaneously (primary EM) or secondary to neurological diseases, autoimmune diseases, or myeloproliferative disorders (secondary EM). Episodes may be triggered by increased body temperature, alcohol, and eating spicy foods. About 15% of cases are caused by mutations in the SCN9A gene and are inherited in an autosomal dominant manner. Other cases may be caused by unidentified genes or by non-genetic factors. Treatment depends on the underlying cause and may include topical and/or oral medications. In some cases, the condition goes away without treatment.