Atopic dermatitis belongs to the group of often concurrent conditions known as atopy. This is a group of diseases that trigger hypersensitivity reactions: an exaggerated defense response of the immune system when in contact with allergens. Other common atopic syndromes include allergic rhinitis (popularly known as hay fever), allergic rhinoconjunctivitis (allergic rhinitis with conjunctivitis), and allergic asthma.
The affected individuals suffer from recurrent bouts of eczema at typical sites of predilection, often including the backs of the knees and elbows, neck, and cleavage area. Patients report chronically dry, cracked, and itchy skin, with increased trans-epidermal water loss, which is a measure of the diffusion of water vapor through the skin. There is also the so-called “minor” variant, where the eczema is present only in small herds, such as around the eyes or on the extremities, without manifesting the full clinical picture of atopic dermatitis.