Atopic eczema

Tahera ChaudryFebruary 2009

Atopic eczema

Atopic eczema (atopic dermatitis) is a chronic inflammatory itchy skin condition that develops in early childhood in the majority of cases

Relapsing/remitting atopic eczema often has a genetic component that leads

to the breakdown of the skin barrier Often environmental triggers many cases of atopic eczema clear or improve during

childhood, whereas others persist into adulthood some children who have atopic eczema will go on to

develop asthma and/or allergic rhinitis; this sequence of events is sometimes referred to as the 'atopic march‘

The serum levels of IgE may be raised.

Approximately 30% of the UK are atopic but the incidence of atopic dermatitis is about 3 - 10%.

It is less common but more severe and persistent in certain ethnic groups such as the Chinese than than in caucasians.

About 50% of patients develop the condition within the first year of life. By 5 years, 87% have developed their condition. Less than 2% develop after the age of 20 years.

The condition improves with age - about 50% resolve by the age of 13 years. Few cases persist beyond 30 years.

Diagnosis

Atopic eczema should be diagnosed when a child has an itchy skin condition plus three or more of the following:

visible flexural dermatitis involving the skin creases, such as the bends of the elbows or behind the knees (or visible dermatitis on the cheeks and/or extensor areas in children aged 18 months or under)

personal history of flexural dermatitis (or dermatitis on the cheeks and/or extensor areas in children aged 18 months or under)

personal history of dry skin in the last 12 months

personal history of asthma or allergic rhinitis (or history of atopic disease in a first-degree relative of children aged under 4 years)

onset of signs and symptoms under the age of 2 years (this criterion should not be used in children aged under 4 years)

Diagnosis (2)

From time to time, most people have acute flares with inflamed, red, sometimes blistered and weepy patches. In between flares, the skin may appear normal or suffer from chronic eczema with dry, thickened and itchy areas.

NB in Asian, black Caribbean and black African children, atopic eczema can affect the extensor surfaces rather than the flexures, and discoid (circular) or follicular

(around hair follicles) patterns may be more common

Infantile

Infants less than one year old often have widely distributed eczema. The skin is often dry, scaly and red with small scratch marks made by sharp baby nails.

The cheeks of infants are often the first place to be affected by eczema.

The napkin area is frequently spared due to the moisture retention of nappies. Just like other babies, they can develop irritant napkin dermatitis

if wet or soiled nappies are left on too long.

Toddlers and pre-school age

As children begin to move around, the eczema becomes more localised and thickened. Toddlers scratch vigorously and the eczema may look very raw and uncomfortable.

Eczema in this age group often affects the extensor aspects of joints, particularly the wrists, elbows, ankles and knees. It may also affect the genitals.

As the child becomes older the pattern frequently changes to involve the flexor surfaces of the same joints (the creases) with less extensor involvement. The affected skin often becomes lichenified i.e. dry and thickened from constant scratching and rubbing,

In some children the extensor pattern of eczema persists into

later childhood.

Toddler and pre-school

School age

Older children tend to have the flexural pattern of eczema and it most often affects the elbow and knee creases. Other susceptible areas include the eyelids, earlobes, neck and scalp.

They can develop recurrent acute itchy blisters on the palms, fingers and sometimes on the feet, known as pompholyx or vesicular hand / foot dermatitis.

Many children develop a 'nummular' pattern of atopic dermatitis. This refers to small coin-like areas of eczema scattered over the body. These round patches of eczema are dry, red and itchy and may be mistaken for ringworm (a fungal infection).

Mostly the eczema improves during school years and it may completely clear up by the teens, although the barrier function of the skin is never entirely normal.

School age

Adults

Adults who have atopic dermatitis may present in various different ways.

They may continue to have a diffuse pattern of eczema but the skin is often more dry and lichenified than in children.

Commonly adults have persistent localised eczema, possibly confined to the hands, eyelids, flexures, nipples or all of these areas.

Recurrent staphylococcal infections may be prominent.

Atopic dermatitis is a major contributing factor to occupational irritant contact dermatitis. This most often affects hands that are frequently exposed to water, detergents and /or solvents.

Hand dermatitis in adult atopics tends to be dry and thickened but may also be blistered.

Adults

Assessment

Detailed history Time of onset, pattern, severity Response to previous and current treatments Poss trigger factors Impact on child and parents Dietary history Growth and development Personal and family history of atopic disease

Consider using tools to assess QoL and family impact

Provide verbal and written advice/education, and practical demos

Management

In children, NICE suggest a treatment schema based on severity: mild atopic eczema

emollients mild potency topical corticosteroids

moderate atopic eczema emollients moderate potency topical corticosteroids topical calcineurin inhibitors e.g. pimecrolimus bandages

severe atopic eczema emollients potent topical corticosteroids topical calcineurin inhibitors bandages phototherapy systemic therapy

Referral criteria

Most children with atopic eczema can be managed in primary care. They should, however, be referred to a specialist service if

****severe infection with herpes simplex (eczema herpeticum) is suspected

*** the disease is severe and has not responded to appropriate therapy in primary care

*** the rash becomes infected with bacteria (manifest as weeping, crusting, or the development of pustules), and treatment with an oral antibiotic plus a topical corticosteroid has failed

** the rash is giving rise to severe social or psychological problems; prompts to referral should include sleeplessness and school absenteeism

** treatment requires the use of excessive amounts of potent topical corticosteroids

Referral criteria (2)

* management in primary care has not controlled the rash satisfactorily. Ultimately, failure to improve is probably best based upon a subjective assessment by the child or parentfor example, the child is having 1-2 weeks of flares per month or is reacting adversely to many emollients

* the patient or family might benefit from additional advice on application of treatments (bandaging techniques)

* contact dermatitis is suspected and confirmation requires patch-testing (this is rarely needed)

* dietary factors are suspected and dietary control a possibility + the diagnosis is, or has become, uncertain

Times will be discretionary and depend on clinical circumstances within a day. maximum waiting time of 2 weeks is appropriate for the urgent category.

Complications

Cutaneous infection occurs secondary to reduced immunity and reduced barrier function of skin:

viral infections - herpes simplex causing eczema herpeticum; warts; molluscum contagiosum;

bacterial infection - colonisation of epidermis by staphylococcal aureus; frank staphylococcal infection such as impetigo

atopic cataract - often bilateral, peak incidence between 15 and 25 years; also, increased risk of developing corticosteroid induced cataracts

growth retardation - affects about 10% of children; not thought to be due to steroid therapy

Prognosis

Good Prognostic indicators: early onset and typical involvement - flexural surfaces 90% resolution by early teens may be recurrence of the disorder in adulthood if there are

circumstances where there is undue stress of the skin eg the hands of a hairdresser

Poor Prognostic indicators: a more guarded prognosis should be given to those where

the condition has a later onset and/or a atypical pattern of involvement (ie extensor surfaces).

References

http://www.nice.org.uk/Guidance/CG57/QuickRefGuide/pdf/English NICE guidance on atopic eczema in children 2007

http://www.dermnetnz.org/dermatitis/atopic.html