Atopic Dermatitis and Eczema

Atopic eczema is a chronic, relapsing, inflammatory skin condition characterized by an itchy red rash that favours the skin creases such as the folds of the elbows or behind the knees.

• Atopic eczema is common and the prevalence is increasing. Eczema affects 15-20% of school children and 2-10% of adults.¹
• The large majority (about 80%) of cases present before the age of 5 years.

• Genetic factors: increased prevalence in those with an affected parent.
• Environmental irritants and allergens:
  • Irritants, e.g. soap, detergents, and chemicals.
  • Staphylococcus aureus is believed to be an important exacerbating factor in atopic eczema¹
  • Extremes of temperature and humidity. Most patients improve in summer and are worse in winter. Sweating induced by heat or exercise can provoke an exacerbation.²
  • Abrasive fabrics, e.g. wool.
  • Dietary factors aggravate atopic eczema in about 10% of children but much less frequently in adults.³
  • Inhaled allergens, e.g. house-dust mites, pollens, pet dander and moulds.²
• Endogenous factors:
  • Stress may exacerbate atopic eczema, which itself may be a cause of psychological distress.²
  • Hormonal changes in women: e.g. premenstrual flare-ups, deterioration in pregnancy

• Must have¹ an itchy skin condition (or report of scratching or rubbing in a child) plus three or more of the following:
  • History of itchiness in skin creases such as folds of the elbows, behind the knees, fronts of ankles, or around neck (or the cheeks in children under 4 years)
  • History of asthma or hay fever (or history of atopic disease in a first-degree relative in children under 4 years)
  • General dry skin in the past year
  • Visible flexural eczema (or eczema affecting the cheeks or forehead and outer limbs in children under 4 years)
  • Onset in the first 2 years of life (not always diagnostic in children under 4 years)
• If it does not itch it is very unlikely to be eczema.

• The distribution tends to vary with age and the appearance of persistent lesions may alter with scratching.
• A tendency to dry skin persists throughout life.
• Acute flare-ups vary in appearance, from vesicles to areas of poorly demarcated redness. Other possible features include crusting, scaling, cracking and swelling of the skin.
• Repeated scratching often leads to thickening of chronic lesions.
• During infancy, atopic eczema primarily involves the face, the scalp and the extensor surfaces of the limbs. It is usually acute. The nappy area is usually spared.
• In children and in adults with long-standing disease, eczema is often localized to the flexure of the limbs.
• Adults: often generalized dryness and itching.
• Chronic eczema on the hand may be the primary manifestation.
• Bacterial infection is suggested by:
  • Crusting, weeping, pustulation and/or surrounding cellulitis with erythema of otherwise normal-looking skin
  • A sudden worsening of the condition

• Psoriasis
• Contact dermatitis
• Seborrhoeic dermatitis
• Fungal infections
• Lichen simplex chronicus
• Scabies and other infestations

• Investigations are rarely required to establish the diagnosis.
• Estimation of IgE and specific radioallergosorbant tests (RASTs) only confirm the atopic nature of the individual.
• Swabs for bacteriology are particularly useful if patients do not respond to treatment, in order to identify antibiotic-resistant strains of S. aureus or detect additional streptococcal infection.

Atopic eczema is associated with other atopic disease such as asthma and hay fever.

• Provide information about the condition, the factors that may provoke it, the role of different treatments, and their effective and safe use. It is important to emphasise the correct quantities of topical treatments to use. Use written information to reinforce information discussed
• Provide support: living with skin disease, especially the potential psychosocial difficulties, can be very difficult.
• Identifying and avoid provoking factors. Allergen avoidance is ineffective in the vast majority of patients.¹ Avoid anything that is known to increase disease severity, advise avoidance of extremes in temperature and humidity, avoiding irritating clothes containing wool or certain synthetic fibres (use non-abrasive clothing fabrics, such as cotton)
• Advise keeping nails short and avoid use of soaps or detergents, replace with emollient substitutes (use gloves when unable to avoid handling irritants such as detergents)
• Keep skin hydrated: use of baths and bath additives and reduce water loss by the use of sufficient appropriate emollient therapy used liberally.

Emollients

• Are best applied when the skin is moist but they should also be applied at other times
• Should be applied as liberally and frequently as possible and continual treatment with complete emollient therapy (combinations of cream, ointment, bath oil and emollient soap substitute) will help provide maximal effect
• Ideally the frequency of application of emollients should be every 4 hours or at least 3-4 times per day
• Should be prescribed in large quantities with the recommended quantities used in generalised eczema being 500 g/week for an adult and 250 g/week for a child
• Intensive use of emollients will reduce the need for topical steroids.
• Education on how to use emollients is essential to ensure maximal rehydration of the skin.

Topical steroids

• Mild corticosteroids are generally used on the face and on flexures; potent corticosteroids are generally required for use on adults with discoid or lichenified eczema or with eczema on the scalp, limbs, and trunk.
• It is recommended that topical corticosteroids for atopic eczema should be prescribed for application only once or twice daily.⁴
• Steroid use should be limited to a few days to a week for acute eczema and up to 4-6 weeks to gain initial remission for chronic eczema
• The weakest steroid should be chosen to control the disease effectively; this may include either a step-up approach, low to more potent, or a step-down approach, more potent to less potent
• Very potent steroids should not be used in children with atopic eczema in primary care. Very rarely their use may be indicated in resistant severe eczema on the hands and feet of adults, again with regular review of use
• Patients using moderate and potent steroids must be kept under review for both local and systemic side-effects
• Chronic eczema in adults: often requires a potent steroid together with emollients and allergen avoidance.

Bacterial infection

• Emollient antimicrobial preparations can help prevent infection
• Oral antibiotics are often necessary in moderate to severe infection; a 14-day course should be given
• Oral flucloxacillin is usually most appropriate for treating S. aureus and erythromycin used if there is penicillin allergy or penicillin resistance
• Penicillin should be given if beta-haemolytic streptococci are isolated
• Steroid-antibiotic combinations are effective in clinical practice although there is no evidence for greater efficacy.

Lichenification

• Results from repeated scratching.
• Initially treated with a potent corticosteroid.
• Bandages containing ichthammol paste (to reduce pruritus) and other substances such as zinc oxide may be applied over the corticosteroid.
• Coal tar and ichthammol can be useful in some cases of chronic eczema.⁵

Exudative eczema

• Initially requires a potent corticosteroid.
• Infection may also be present and requires treatment.
• Potassium permanganate solution (1 in 10 000) can be used in exudating eczema for its antiseptic and astringent effect.

Severe refractory eczema

• Requires management under specialist supervision.
• May require phototherapy, systemic corticosteroids or other drugs acting on the immune system, e.g. ciclosporin, azathioprine, mycophenolate mofetil.

Managing flare-ups

• Settle inflammation with topical corticosteroids.
• Treat clinically apparent bacterial infection with oral antibiotics; moderate and severe infection requires a 14 day course of flucloxacillin (or erythromycin if penicillin allergy).¹
• Urgently refer or admit someone with severe unresponsive disease. Admit anyone with suspected herpes simplex virus infection (eczema herpeticum).
• Managing frequent flare-ups
  • Change the emollient to one with a higher lipid content.
  • Advise the person to apply the emollient more often.
  • Recommend applying more emollient each time.
  • Review the factors that might be provoking flare-ups; avoid environmental irritants and stresses where possible.

Tacrolimus and pimecrolimus for atopic eczema

• NICE has recommended that topical pimecrolimus and tacrolimus are options for atopic eczema not controlled by maximal topical corticosteroid treatment or if there is a risk of important corticosteroid side-effects (particularly skin atrophy).⁶
• Topical pimecrolimus is recommended for moderate atopic eczema on the face and neck of children aged 2-16 years.
• Topical tacrolimus is recommended for moderate to severe atopic eczema in adults and children over 2 years.

Recommendations for referral to secondary care¹:

• 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
• 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 parent
• 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 is a possibility
• The diagnosis is, or has become, uncertain.

• Infection:
  • Staphylococcus aureus infection may present with typical impetigo or as worsening of the eczema with increased redness, oozing, and crusting.
  • Herpes simplex infection, indicated by grouped vesicles and punched-out erosions, can also occur. Disseminated herpes simplex virus infection, eczema herpeticum, presents with widespread lesions that may coalesce to large, denuded, bleeding areas that can extend over the entire body. Superficial fungal infections are also more common in people with atopic eczema.
• Psychosocial impact
  • Disturbed sleep patterns.
  • Reduced self-esteem because of chronic visible disease.
  • Isolation from other children, e.g. when they are unable to swim.
  • Adverse effects on a child's behaviour and development: poor sleep, reduced self-esteem, and social isolation.

• Usually a relapsing course, with a tendency to gradual improvement in adult life.
• Atopic eczema can be expected to clear in 60-70% of children by their early teens, although relapses may occur.³
• Predictors of a worse prognosis include:
  • Onset at an age of 3-6 months
  • Severe disease in childhood
  • Associated asthma or hay fever
  • Small family size
  • High IgE serum levels.³