Atopic dermatitis

Atopic dermatitis, also known as atopic eczema, is a common, chronic, episodic condition of skin barrier dysfunction which makes the skin dry and itchy, and vulnerable to inflammation and infection. Onset is usually in the first year of life. It may resolve permanently, but may also persist into adulthood. Daily management with topical treatments and avoidance of environmental triggers is essential, but is costly and requires much time and attention from patients and carers. Poor treatment and management risks severe impairment of physical and mental health.

Atopic dermatitis is characterised by dry, fissured, itchy skin, and inflamed, vesicular lesions associated with exudate and exfoliation. Skin becomes lichenified and excoriated by scratching (Figure 1). Clinical features vary in different types of skin (Stanway and Jarrett, 2021).

Secondary infections, particularly with Staphylococcus aureus are common. Staphylococcal infection appears as inflamed, wet and weepy skin with exudate drying to form golden crusts (Figure 2). Secondary infection with herpes simplex virus presents with areas of impetigo, commonly on the face, characterised by punched-out erosions and tense vesicles (Figure 3).

In addition to the irritation of atopic dermatitis symptoms, patients may experience disturbed sleep, leading to impaired functioning in daily activities, school, work and leisure. The visibility of atopic dermatitis symptoms often causes patients embarrassment and low self-esteem, and may also provoke others to stigmatise and ostracise them, resulting is social isolation and impaired social relationships (Papadopoulos and Bor, 1999).

Atopic dermatitis

The causes of atopic dermatitis are complex, poorly understood and the subject of ongoing research. They include immunological and environmental factors. Atopic dermatitis is associated with atopic conditions such as hay fever and asthma, and has a strong genetic component related to regulation of immunoglobulin E (IgE) synthesis (Morar et al, 2006).

Dryness and damage to the skin barrier allows water loss and the penetration of irritants or allergens from the environment (Figure 4). Triggers include (Stanway, 2004):

• Irritants, for example soap, detergent, solvents, cosmetics, perfumes, woollen or synthetic clothing and skin creams
• Allergens, for example grass and tree pollens, house dust-mite antigens and microbes.

Symptoms can also be triggered by stress (NICE, 2021; Stanway, 2004):

• Physical stress, for example a cold or other illness; premenstrual hormonal changes and pregnancy; scratching (the ‘itch-scratch cycle’)
• Mental stress, for example depression, distress in response to symptoms of atopic dermatitis
• Social stress, for

Signs of atopic dermatitis are itching, or evidence of scratching, with three or more of the following:

• History of itching in the skin creases and flexures, or (in children <4 months) on the cheeks
• Personal or family history of asthma, hay fever or eczema
• Persistent dry skin
• Signs of changes to the skin, for example lichenification or inflammation
• Onset in the first 2 years of life.

NICE (2021) defines five categories of severity:

• Clear skin
• Mild: areas of dry skin, and infrequent itching with or without small areas of redness
• Moderate: areas of dry skin, frequent itching, and redness with or without excoriation and localised skin thickening
• Severe: widespread areas of dry skin, incessant itching and redness with or without excoriation, extensive skin thickening, bleeding, oozing, cracking, and alteration of pigmentation
• Infected: weeping, crusted, pustular skin, with fever or malaise.

It is essential to discuss management strategies with patients and parents/carers to ensure that they are appropriate for the individual’s needs and encourage adherence with treatment. Patients and parents/carers may need a practical demonstration of how to apply topical treatments.

It may also be helpful to discuss ways to avoid symptom triggers, such as:

• Using a soap substitute without sodium lauryl sulfate (SLS) (British Association of Dermatologists, 2021a)
• Wearing gloves to protect the hands from detergents and other irritants
• Washing clothes in diluted, non-perfumed washing powder
• Reducing irritants and allergen load in the home, for example dust.