Atopic eczema (atopic dermatitis )



Background

  • Itchy, cracked, dry, sore skin areas
  • Hands, flexor surfaces of elbows & knees (face, scalp in children)
  • Multifactorial aetiology
  • Adults : children = 80:20
  • FHx, also seen with asthma / rhinitis
  • Flare ups may be triggered by detergent, cold weather food allergens
  • Cell mediated IgE hypersensitivity rxn

Clinical

Clinical Diagnosis

Itchy skin and at least 3 of:

  • Visible flexural dermatitis involving the skin creases (or visible dermatitis on the cheeks and/or extensor areas in children ≤ 18 months)
  • Personal history of flexural dermatitis
  • Personal history of dry skin in the last 12 months
  • Personal history of asthma or allergic rhinitis (or history of atopic disease in a first-degree relative if the patient is <4 years old)
  • Onset of signs and symptoms <2 years

Very rarely a punch Bx may be required.


Differential Dx

Common DDx for atopic eczema
Condition   Ages Characteristics
Seborrhoeic eczema   Infants Characteristic non-pruritic greasy scales (esp. scalp/nappy). Appears in first 6 weeks of life and spond. resolves in weeks
Seborrhoeic eczema   Adults Erythematous patches with yellow, white or greyish scales in seborrhoeic area esp. face, scalp chest
Nummular (discoid) eczema   Children and adults Coin-shaped scaly patches on legs or buttocks &plusmn; itch
Irritant contact dermatitis   Children and adults Acute ot chronic eczematous lesions at sites of exposure, typically less itchy than atopic eczema
Allergic contcat dermatitis   Children and adults Well-circumscribed erythematous rash with max. expression at exposure sites
Asteatotic eczema   Adults Scaly, fissured patches of dermatitis on dry skin, esp. legs
Psoriasis   Adults and children Well efined red scaly plaques (extensor surfaces, nails, scalp)
Dermatophyte infesction   Children and adults One or more demarcated scaly plaques with central clearing ±itch
Impetigo   Children Demarcated erythematous patches with blisters or honey-yellow crusting
Scabies   Children Itchy superficial burrows and pustules on palms and soles, between fingers and genitalia

Complications

  • Skin barrier dysregulation - prone to infection
  • Staph. aureus - weeping, crusting, pustules, constitutional Δ
  • Eczema herpericum - HSV - severe infection
  • Molloscum contagiosum
  • Fungal infectuions (M.furfur) - local scales

Management

  • Emollients to stop the skin drying (not aqueous cream as it may irritate skin)
  • Topical steroid cream / ointments (lowest effective potency dose first) to reduce inflammation during flare up
  • Topical calcineurin inhibitors (tacrolimus). Second line. Block T-cell activation without causing skin atrophy
  • Treatments for any superadded infections (bact/viral/fungal)
  • Antihistamines if itch causing insomnia
  • Wet wrap therapy and phototherapy from dermatologist only


References


Content By Dr Íomhar O' Sullivan . Last review Dr ÍOS 10/06/21.