Atopic Eczema

Introduction

Atopic eczema, also known as atopic dermatitis, is a chronic, inflammatory skin condition characterised by dry, itchy, and inflamed skin. It is most common in children but can persist into adulthood or develop later in life. Atopic eczema is often associated with other atopic conditions, such as asthma and allergic rhinitis, and can significantly impact quality of life due to its chronic nature and potential for flare-ups.

Aetiology and Risk Factors

The exact cause of atopic eczema is not fully understood, but it is believed to result from a combination of genetic, environmental, and immunological factors:

• Genetic Predisposition: Individuals with a family history of atopic diseases (eczema, asthma, allergic rhinitis) are more likely to develop atopic eczema. Mutations in the filaggrin gene, which is involved in skin barrier function, are also linked to an increased risk.
• Immune System Dysregulation: Atopic eczema is associated with an overactive immune response, leading to inflammation and an impaired skin barrier.
• Environmental Triggers: Exposure to allergens (such as dust mites, pollen, and pet dander), irritants (such as soaps, detergents, and certain fabrics), and changes in weather (especially cold, dry conditions) can trigger or exacerbate eczema symptoms.
• Skin Barrier Dysfunction: An impaired skin barrier allows moisture to escape and allergens or irritants to penetrate, leading to dry, cracked skin that is more prone to inflammation and infection.
• Stress: Psychological stress is known to exacerbate eczema symptoms, likely due to its effects on immune function and skin barrier integrity.

Clinical Presentation

Atopic eczema can present with a variety of symptoms, which may vary depending on the age of the patient:

• Dry, Itchy Skin: Intense itching is a hallmark of atopic eczema, often leading to scratching and further skin damage.
• Erythema: Red, inflamed patches of skin are common, particularly in areas prone to friction or moisture, such as the face, neck, elbows, and knees in children, and the hands, wrists, ankles, and feet in adults.
• Vesicles and Oozing: In more severe cases, small blisters (vesicles) may develop, which can ooze and form crusts, particularly during flare-ups.
• Skin Thickening (Lichenification): Chronic scratching can lead to thickened, leathery skin, known as lichenification, particularly in areas of repeated friction or irritation.
• Hyperpigmentation or Hypopigmentation: Prolonged inflammation and healing can cause changes in skin pigmentation, leading to areas of darker or lighter skin.
• Secondary Infection: The compromised skin barrier makes individuals with atopic eczema more susceptible to bacterial infections, such as impetigo, caused by Staphylococcus aureus, or viral infections, such as eczema herpeticum.

Diagnosis

The diagnosis of atopic eczema is primarily clinical, based on the patient’s history and physical examination. Key diagnostic criteria include:

• History of Itching: Persistent itching is a central feature of atopic eczema.
• Typical Distribution: The presence of eczema in typical locations, such as the face and extensor surfaces in infants, or the flexural areas in older children and adults, supports the diagnosis.
• Personal or Family History of Atopy: A history of atopic conditions, such as asthma, allergic rhinitis, or eczema, in the patient or family members is often present.
• Chronic or Relapsing Course: Atopic eczema often follows a chronic or relapsing course, with periods of remission and exacerbation.
• Exclusion of Other Diagnoses: Other skin conditions, such as contact dermatitis, psoriasis, and seborrhoeic dermatitis, should be excluded.

Management

Management of atopic eczema involves a combination of skincare, pharmacotherapy, and lifestyle modifications aimed at reducing symptoms, preventing flare-ups, and maintaining skin integrity:

1. Skincare

• Emollients: Regular use of emollients is the cornerstone of eczema management. They help maintain skin hydration, restore the skin barrier, and reduce itching. Emollients should be applied liberally and frequently, particularly after bathing.
• Avoiding Irritants: Patients should avoid known irritants, such as harsh soaps, detergents, and fabrics that can exacerbate eczema. Mild, fragrance-free cleansers and moisturisers are recommended.

2. Pharmacotherapy

Topical corticosteroids are the mainstay of treatment for managing flare-ups. The potency of the steroid should be matched to the severity of the eczema and the area of the body being treated:

• Low Potency: Hydrocortisone 1% is typically used for mild eczema, particularly on sensitive areas such as the face or in infants.
• Moderate Potency: Clobetasone butyrate 0.05% or betamethasone valerate 0.025% are used for moderate eczema on areas such as the limbs and trunk.
• High Potency: Betamethasone valerate 0.1% or mometasone furoate 0.1% are used for more severe eczema or in areas with thickened skin, such as the palms or soles.
• Very High Potency: Clobetasol propionate 0.05% is reserved for severe eczema and is typically used under specialist supervision, especially on areas with thick plaques or lichenification.

• Topical Calcineurin Inhibitors: Tacrolimus and pimecrolimus are non-steroidal alternatives that can be used for sensitive areas (such as the face and neck) or for long-term maintenance in patients who cannot tolerate corticosteroids.
• Antihistamines: Sedating antihistamines can be used at night to reduce itching and improve sleep, particularly during acute flare-ups.
• Antibiotics: If there is evidence of secondary bacterial infection, such as crusting or weeping, topical or oral antibiotics may be required.

3. Lifestyle Modifications

• Bathing Practices: Bathing should be done with lukewarm water and for a limited duration to avoid drying out the skin. Emollients should be applied immediately after bathing to lock in moisture.
• Managing Triggers: Identifying and avoiding triggers, such as certain foods, allergens, or stress, can help reduce the frequency and severity of flare-ups.
• Stress Management: Stress reduction techniques, such as mindfulness, relaxation exercises, and adequate sleep, can help manage eczema symptoms.

Prevention and Lifestyle Modifications

While atopic eczema cannot be completely prevented, the following measures can help reduce the frequency and severity of flare-ups:

• Consistent Skincare Routine: Regular use of emollients and gentle skincare products can help maintain the skin barrier and reduce the likelihood of flare-ups.
• Avoiding Known Triggers: Patients should avoid exposure to known allergens and irritants, such as certain foods, pet dander, dust mites, and harsh chemicals.
• Climate Control: Maintaining a cool, humid environment can help prevent skin dryness and irritation.
• Dietary Considerations: In some cases, dietary modifications, such as avoiding certain foods, may be beneficial, particularly if food allergies are suspected to be a trigger.

When to Refer

Referral to a dermatologist or specialist is recommended in the following situations:

• Severe or Widespread Eczema: If the eczema is severe, extensive, or not responding to standard treatments, referral to a dermatologist is advised for further evaluation and management.
• Recurrent Infections: If the patient has recurrent secondary bacterial or viral infections (such as eczema herpeticum), specialist care is needed.
• Uncertain Diagnosis: If the diagnosis is unclear or if other skin conditions need to be excluded, referral to a specialist may be necessary.

References

1. National Institute for Health and Care Excellence (2024) Atopic Eczema in Under 12s: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/cg57 (Accessed: 26 August 2024).
2. British Association of Dermatologists (2024) Guidelines for the Management of Atopic Eczema. Available at: https://www.bad.org.uk (Accessed: 26 August 2024).
3. British National Formulary (2024) Topical Corticosteroids and Emollients. Available at: https://bnf.nice.org.uk/ (Accessed: 26 August 2024).