The Hanifin and Rajka criteria

In 1980, Hanifin and Rajka published a list of all the possible signs and symptoms of dermatitis, divided into major and minor features. This list was found to be cumbersome for daily practice, so they prepared a shortened version:

Major features :

• Pruritus
• Early age of onset
• Typical morphology and distribution; flexural lichenification and linearity in adults; facial and extensor involvement during infancy and childhood
• Chronic or chronically relapsing dermatitis
• Personal or family history of atopy (asthma, allergic rhinoconjunctivitis, atopic dermatitis)

Minor or less specific features :

• Xerosis
• Ichthyosis/palmar hyperlinearity/keratosis pilaris
• Immediate (i.e. type 1) skin response
• Hand/foot dermatitis
• Cheilitis
• Nipple eczema
• Susceptibility to cutaneous infections (especially Staphylococcus aureus and Herpes simplex)
• Perifollicular accentuation

The short version also includes major and minor criteria. The major criteria are all based on clinical appearance or the patient's history, and they are therefore relatively easy to check. They consist of 5 items: pruritus (itch), early age of onset, typical lesions and distribution, chronic or chronically relapsing, and a family history of atopy. There are 7 clinical items in the minor criteria list, but only a few are highlighted here because of their importance and the relative difficulty in finding good definitions for them:

• Xerosis is reported in 75% of patients with atopic dermatitis. It appears as a non- inflammatory scaling over a large surface area of the body and its usually more visible in winter than in spring. In other words, when the skin is dry (and appears so). It's been shown that xerosis is the result of a hereditary deficiency in the keratinocyte (the cell that forms the superficial layer of the skin) in retaining water.
• Ichtyosis describes large fish-scale plaques of the skin.
• Keratosis pilaris is a "chicken" type of dry skin, especially seen on the upper arms and buttocks.
• Palmar linearity describes an exaggeration of the creases and lines on the palms.
• Cheilitis is eczema of the upper and lower lips.
• Perifollicular accentuation is similar to keratosis pilaris.

The minor criteria also include a skin-prick or skin-patch test, but since this is not essential for the diagnosis, it isn't discussed further here. You can go to visit the Dermatology Online Atlas to see pictures of the various skin lesions mentioned in the list -- see link below.

According to the authors, 4 criteria from this list must be present to establish a diagnosis of atopic dermatitis.

The UK Atopic Dermatitis Working Party Criteria

In 1994 this working group published an even more simplified list of criteria for the diagnosis of atopic dermatitis, which is intended for use in children over 2 who complain of itchy skin, or report scratching or rubbing. If 3 or more of the items in the list below are present, then a diagnosis of atopic dermatitis is highly likely:

• A history of involvement of the skin creases (the folds of the elbows, the fronts of the ankles, around the neck, or the cheeks in children less than 4 years old).
• A history of asthma or hay fever in the patient, or of atopic disease in a first-degree relative (i.e. mother, father, bother or sister) if the child is less than 4 years old.
• A history of general dry skin in the past year.
• Visible dermatitis in the skin flexures (or dermatitis of the cheeks, forehead and outer limbs in children less than 4 years old).
• Onset during the first 2 years of life (but this isn't used for children less than 4 years old).

It's important to get an accurate diagnosis of atopic dermatitis if the best treatment is to be given.