Dermatitis is a broad term referring to a group of conditions causing inflammation of the epidermis, the top layer of the skin.
The words dermatitis and eczema are often used interchangeably, although technically the term eczema refers to a particular type of dermatitis, also known as atopic dermatitis. There are many types of dermatitis.
Atopic dermatitis has a genetic component, and commonly presents in childhood. It’s often associated with asthma and hayfever.
Irritant contact dermatitis develops when the skin is irritated by a variety of environmental factors, such as water, detergent, chemicals and friction. Dermatitis on the hands resulting from frequent hand washing is a common presentation of irritant contact dermatitis.
Allergic contact dermatitis is a form of dermatitis caused by an allergic reaction to a substance contacting the skin, for example certain preservatives, fragrances and nickel, amongst many others. A rash on the earlobe from nickel-containing earrings is a common presentation of allergic contact dermatitis.
Seborrhoeic dermatitis is a form of dermatitis that presents in seborrhoeic, or oily areas of the skin, such as the scalp, face and chest. It occurs in response to a yeast called Malasezzia which lives on the skin. It can present as ‘cradle cap’ in babies, and ‘dandruff’ in adults.
Perioral (or periorificial) dermatitis presents as red bumps around the mouth, nose and eyes. It’s most common in young women, and can develop in response to the use of topical corticosteroids or occlusive skincare products and cosmetics, and some cosmeceuticals.
