Diagnostic criteria for atopic eczema in children and adults2
Atopic eczema is likely if the following criteria are fulfilled (although other conditions may need to be excluded):
An itchy skin condition (or parental report of scratching) in the last 12 months, plus three or more of the following2:
A history of involvement of the skin creases (fronts of elbows, behind knees, fronts of ankles, around neck, or around eyes).
A personal history of asthma or hay fever (or history of atopic disease in a first degree relative if a child is less than 4 years of age).
A history of generally dry skin in the last year.
Onset under the age of 2 years (not used if a child is less than 4 years of age).
Visible flexural eczema (including eczema affecting cheeks or forehead and outer aspects of limbs in children less than 4 years of age).
Note that these criteria apply to all ages, social classes, and ethnic groups. However, in children of Asian, black Caribbean, and black African ethic groups, atopic eczema can affect the extensor surfaces rather than the flexures, and discoid or follicular patterns may be more common.
The distribution and appearance of eczematous rashes can be detailed by2:
- Infancy: eczema primarily involves the face, the scalp, and the extensor surfaces of the limbs. The nappy area is usually spared.
- Children: longstanding eczema; localization to the flexure of the limbs is more likely.
- Adults: flexure involvement with generalised dryness and itching, particularly with exposure to irritants. Eczema on the hands may be the primary manifestation.
- Acute eczema (flares): vary in appearance, from poorly demarcated redness to fluid in the skin (vesicles), scaling, or crusting of the skin.
- Chronic eczema: affected skin becomes thickened (lichenified) as a result of repeated scratching.
The table below summarises the NICE Guidelines on the assessment of the physical and psychosocial severity of eczema:
From NICE Clinical Guidelines CG57: Atopic eczema in children. December 2007.
In addition, it may be appropriate to use objective tools to assess the impact of eczema on psychosocial wellbeing, such as the DLQI (Dermatology Life Quality Index). Versions of the DLQI are available for measuring quality of life in infants, children and adults. These questionnaires can be accessed online via the Department of Dermatology at Cardiff University:6
There is also the Patient-Oriented Eczema Measure (POEM) for severity, accessed online via the Centre of Evidence Based Dermatology at the University of Nottingham:7
The NHS Clinical Knowledge Summary on atopic eczema, based on guidelines from the British Association of Dermatologists, outlines the following common differential diagnoses:2
- Psoriasis: this is less itchy than eczema, is well circumscribed and reddish, featuring flat-topped plaques with a silvery scale, and is typically symmetrical.
- Allergic contact dermatitis: presents as an eczematous rash, at any site related to a topical allergen, in a person of any age.
- Seborrhoeic dermatitis: features red, sharply marginated lesions with greasy scales; is usually confined to areas with sebaceous gland activity (e.g. ears, beard area, eyebrows, scalp, nasolabial folds).
- Scabies and other infestations: these should be suspected when there is recent onset of an itchy rash in a family.