Erythema nodosum is a skin reaction that occurs secondary to many processes, especially infections.
This reaction forms a red nodules and / or purplish skin, about two to three centimeters in diameter, which are often located in the anterior tibia, although it may occur in the arms. They are very painful, especially to the touch. Actually, this is a hypersensitivity reaction of the skin, although its exact mechanism is unknown.
It occurs most often in women between 20 and 30 years without knowing exactly why.
