1. (Plants) any N temperate fagaceous tree of the genus Castanea, such as C. sativa (sweet or Spanish chestnut), which produce flowers in long catkins and nuts in a prickly bur. Compare horse chestnut, water chestnut, dwarf chestnut. 2. (Cookery) the edible nut of any of these trees.
Another condition that is sometimes revealed by investigation of erythema nodosum is sarcoidosis. Drugs, including oral contraceptives, appear to be the cause of particular cases of erythema nodosum. In many cases, however, no clear cause can be found.
Each type of erythema has different causes for the skin changes. However, in most cases, infection and allergic reactions or autoimmune response (the body attacking its own immune system) can account for a majority of these changes. In the case of erythema caused by an infection, this is typically from a virus.