Eczema or atopic dermatitis (from Greek ἔκζεμα ēkzema, "to boil over") is a form of dermatitis,] or inflammation of the epidermis (the outer layer of the skin). The term eczema is broadly applied to a range of persistent skin conditions. These include dryness and recurring skin rashes that are characterized by one or more of these symptoms: redness, skin edema (swelling), itching and dryness, crusting, flaking, blistering, cracking, oozing, or bleeding. Areas of temporary skin discoloration may appear and are sometimes due to healed injuries. Scratching open a healing lesion may result in scarring and may enlarge the rash.
The word eczema comes from Greek words, that mean "to boil over". Dermatitis comes from the Greek word for skin – and both terms refer to exactly the same skin condition. In some languages, dermatitis and eczema are synonymous, while in other languages dermatitis implies an acute condition and "eczema" a chronic one. The two conditions are often classified together.