Eczema

Definition/diagnostic criteria Eczema, synonymous with atopic dermatitis, is a chronic, relapsing inflammatory skin disorder. It’s characterised by intense pruritus, excoriation, erythematous, dry, lichenified, fissured skin and an increased risk of skin infection.

Epidemiology Atopic eczema is most common in children, often developing before their first birthday, but it can also arise in adults. It’s a long-term condition, though it may significantly improve or clear completely in some children as they age.

The triggers for flare-ups can include soap, detergents, overheating, rough clothing, stress, skin infections, and in some cases, allergens like animal dander and house dust mites.

Diagnosis
Clinical features: Appearance varies depending on age, ethnicity, and treatment history.

• The condition can manifest as dry skin, erythema, vesicles, weepy/crusted patches, excoriations, and lichenification.
• Common sites include the face in infants, flexural involvement in children, and potential generalisation in some patients.
• Skin of colour may exhibit specific features like chronic prurigo, prominent follicular involvement and more scales.

Pityriasis alba and lichen simplex are common eczema variants.

• Pityriasis alba presents as patches of hypopigmentation, primarily affecting children and young adults, often associated with atopic dermatitis.
• Lichen simplex, characterized by thickened, leathery skin due to repeated scratching or rubbing, is a response to chronic itching and can co-occur with eczema.

Investigations Investigations for eczema are primarily clinical. However, an HIV test is advised in atypical presentations.

Treatment

• Emollients: Liberal use of emollients as a moisturiser and soap substitute is the mainstay of treatment for eczema. The best emollient is the one the patient will use. Ointments are less likely to cause contact allergic dermatitis as they do not contain preservatives. Moisturisers should be rubbed into the skin until they are no longer visible, and left for 15-20 minutes before steroid creams are applied.
• Topical steroids: Topical steroids should be used for flare-ups and only to inflamed skin. Steroid strength should be determined by age of patient, site and severity and the lowest appropriate potency.

The Primary Care Dermatology Society (PCDS) recommends the following steroids strengths:

• Child, face: mild potency e.g. 1% hydrocortisone.
• Child, trunk and limbs: moderate potency e.g. Eumovate ® (clobetasone butyrate 0.05%) or Betnovate-RD ® (betamethasone valerate 0.025%).
• Adult face: mild or moderate potency e.g. Eumovate ®.
• Adult trunk and limbs: potent e.g. Betnovate ® (betamethasone valerate 0.1%), Elocon ® (mometasone).
• Palms and soles: potent or very potent e.g. Dermovate ® (clobetasol propionate 0.05%).

Take particular care around the eyes (risk of glaucoma), face, in children and on the lower legs in older people and advise patients about the potential side effects, such as skin thinning, with prolonged steroid use.

For frequent flares the PCDS recommends considering a steroid weekend regime with daily application of steroid for two weeks and then alternate day application for two weeks and then treatment on 2 consecutive days a week to reduce frequency of flare ups.

Other treatments include:

• Antihistamines for severe itching, antibiotics for infected eczema.
• Topical calcineurin inhibitors (e.g. topical tacrolimus) at sites at risk of skin atrophy (e.g. around the eyes, flexural sites).

In cases where eczema is severe and not responding to the above treatments, referral to a dermatologist may be necessary. Specialist treatments can include skin bandaging, phototherapy and systemic treatments like oral corticosteroids, immunosuppressants, or biologics.

Prognosis Eczema’s course can be chronic, with periods of exacerbation and remission. While many children see improvement with age, this is not universally the case. The chronic nature of the condition necessitates ongoing management and patient education.