Atopic Dermatitis (Eczema)

Snapshot

A 5-month-old boy is brought to urgent care for a wet rash on his cheeks. His mother reports that he has been dealing with this rash for the past few weeks, though it has gotten much worse in the past few days. She has wrapped his hands in socks to prevent scratching, especially during sleep. Family history includes childhood asthma and eczema. On physical exam, his bilateral cheeks are erythematous with oozing papulovesicles and excoriations. The physician prescribes a topical corticosteroid.

Introduction

Clinical definition
- a chronic and pruritic inflammatory skin disease also known as eczema
Epidemiology
- prevalence
  - very common
  - 10-20% prevalence
- demographics
  - primarily affects children but can affect all ages
- risk factors
  - family history
  - living in urban setting
  - Western diet
Etiology
- combination of genetic, dietary, and environmental causes
Pathogenesis
- filaggrin deficiency or dysfunction may contribute to decreased water retention, impaired tight-junction formation, and reduced ceramide content
- cutaneous inflammation with infiltrating T-cells can cause epidermal thickening, contributing to functional impairment of epidermal barrier
Genetics
- mutations
  - loss of function mutation in filaggrin (FLG) gene
    - filaggrin is an epidermal structural protein
    - increases risk for developing atopic dermatitis and other allergic disorders
Associated conditions
- atopic triad
  - eczema (atopic dermatitis)
  - asthma
  - allergic rhinitis
- food allergy
- Wiskott-Aldrich syndrome
  - suspect when there is eczema along with recurrent infections and thrombocytopenia
- selective IgA deficiency
  - suspect when you have eczema and recurrent sinus, pulmonary, and GI infections
- hyper-IgE syndrome
  - suspect when there is eczema along with recurrent cold abscesses and high serum IgE
Prognosis
- majority of childhood eczema will improve or resolve as they get older
adult eczema often evolve into chronic hand eczema

Presentation

Symptoms
- pruritus
  - may result in sleep disturbance
- excoriations from scratching
Physical exam
- dry and rough skin
- acute flares
  - diffuse erythematous patches and plaques with oozing and crusting papules/vesicles
- chronic lesions
  - poorly demarcated patches and plaques with scales, excoriation, and lichenification
  - hyperlinearity of palms or soles
- location
  - commonly on skin flexures in children and adults
commonly on the face in infancy

Studies

Labs
- may have ↑ serum IgE
Biopsy
- indication
  - to confirm diagnosis
- findings
  - epidermal intercellular edema (spongiosis)
Making the diagnosis
most cases are clinically diagnosed

Differential

Treatment

Conservative
- emollients and moisturizers
  - indications
    - enhances repair of epidermal barrier
    - to apply soon after bathing
Medical
- topical therapy
  - corticosteroids
    - indication
      - first-line treatment for acute flares
    - types
      - low-potency topical steroids
        can use on face and neck
      - medium or high-potency topical steroids
        cannot use on face, neck, or anogenital area
      - adverse effects
        long-term use carries risk of skin atrophy
  - calcineurin inhibitors
    - indications
      - for use on face, anogenital, and neck area
      - for disease recalcitrant to steroids
      - alternative to steroids
    - drugs
      - tacrolimus
- systemic therapy
  - indication
    - for severe or refractory atopic dermatitis
  - drugs
    - cyclosporine
    - azathioprine
    - dupilumab
Procedural
- phototherapy
  - indications
    - for severe or refractory atopic dermatitis
    - for patients not willing to take systemic therapy for atopic dermatitis
  - modalities
    - ultraviolet light therapy
psoralen plus ultraviolet A (PUVA)

Complications