Erythema nodosum

**Definition:** An erythematous eruption commonly associated with drug reactions or infection and characterised by inflammatory nodules that are usually tender, multiple, and bilateral. These nodules are located predominantly on the shins with less common occurrence on the thighs and forearms. They undergo characteristic colour changes ending in temporary bruise-like areas. This condition usually subsides in 3-6 weeks without scarring or atrophy.