Erythromelalgia: diagnosis and classification.

Erythromelalgia is not a commonly recognized or diagnosed condition that affects the lower extremities. The first reported case was in 1878, when Mitchell suggested the term "erythromelalgia." This condition is characterized by a burning sensation with erythema of the involved extremity. When the extremity is lowered, or heat is applied, the pain is intensified. The application of cold or elevation of the extremity will have the opposite effect of decreasing the pain. Erythromelalgia is classified as primary or idiopathic if there is no accompanying disease process. Secondary erythromelalgia is associated commonly with myeloproliferative syndrome-related thrombocythemia, and is mostly evident in adult onset of the condition. Treatment for adults with erythromelalgia includes a single daily dose of aspirin, but children who have no associated underlying disorder find little to no relief with acetylsalicylic acid.