Quick facts!
- Eczema (aka atopic dermatitis) is a chronic pruritic inflammatory skin disease
- Presentation highly variable based on age and severity
- Occurs most often in children, but also affect adults
- Associated with Personal/Family Hx of atopy (eczema, asthma, or allergic rhinitis)
- Associated with elevated serum IgE (up to 80% of patients)
- Onset often before age 5yo (~60% by age <1yo; ~85% by age 5yo)
- ~50% of patients diagnosed in childhood will have persistent eczema
Epidemiology
Affects 5-20% of children worldwide; 11-15% of children in the US
- Limited data on prevalence in adults (7.3% in a cross-sectional study
from 2019 with ~1300 adults in the US)
May occur in any geographic location
- Higher incidence in Western societies, developed countries, and urban areas
- Increasing incidence in Africa, Eastern Asia, Western Europe, and parts of Northern Europe
30-80% of patients are sensitized to certain foods
Risk factors
+Family Hx of atopy present in ~70% patients
- Children with 1 atopic parent have a 2-3-fold ↑ risk; children with 2 atopic parents have a 3-5 fold ↑ risk
Loss-of-function mutations in filaggrin (FLG) gene involved in skin barrier function
Potential protective factors: early exposure to endotoxins, dogs, farm animals, or daycare
Pathophysiology
Characterized by epidermal changes:
- Spongiosis – epidermal edema → stretching of intercellular attachments → rupture → vesicles
- Acanthosis – stratum spinosum overgrowth
- Hyperkeratosis – corneous skin layer hypertrophy
Characterized by lymphohistiocytic infiltrate in dermis
Acute phase primarily characterized by spongiosis
Multifactorial causes:
- Skin barrier deformities
- Innate immunity response abnormalities
- Th2-skewed adaptive immune response
- Altered skin resident microbial flora
General features
Most common features: dry skin + severe pruritus
Cutaneous hyperreactivity to environmental stimuli: allergens, irritants, infections, changes to physical environment or stress
Acute Eczema:
- Very pruritic erythematous papules/vesicles
- Exudation or crusting
Subacute/Chronic Eczema:
- Dry, scaly, or excoriated erythematous papules
Chronic Eczema:
- Skin thickening, fissuring
Clinical features vary by age!
0-2yo:
- Erythematous, pruritic, scaly lesions
- Possible vesicle formation
- Serous exudates and crusting in severe cases
- Extensor surfaces, scalp, or cheeks
- SPARES the diaper area
2-16yo:
- Less exudation, more lichenification
- Flexural surfaces
- Antecubital and popliteal fossae, volar wrists, ankles, and neck
Adults:
- More lichenified and localized
- Flexural surfaces
Classification
Diagnosis
Eczema is a clinical diagnosis: hx, skin lesion appearance/distribution, associated clinical signs
1 MANDATORY CRITERIA: pruritic skin by observation or report
≥3 MAJOR CRITERIA:
- Hx of skin crease involvement
- Hx of asthma or hay fever OR Hx of atopic disease in 1° relative for child <4yo
- Visible dermatitis involving flexural surfaces
- IF <4yo, dermatitis affecting the forehead, cheeks, and outer aspects of extremities
- Grossly dry skin within the past year
- Symptoms starting in a child <2yo
Lab testing and skin biopsy not routinely used or recommended
Differential diagnosis
- Allergic/Irritant Contact Dermatitis: exposure history, specific skin area localization, relevant patch test
- Seborrheic Dermatitis: erythematous patches with greasy scale, scalp involvement, little to no pruritus
- Psoriasis: well-demarcated erythematous patches, little scale, diaper area involvement
- Scabies: vesicopustules on palms/soles, skin fold and diaper area involvement
- Drug reactions
- Nutritional deficiencies
- Primary immunodeficiencies (e.g. Hyperimmunoglobulin E Syndrome, Wiskott-Aldrich syndrome)
- Cutaneous T Cell Lymphoma
Treatment
Check out the 2014 guidelines from the AAD on topical therapies and systemic agents!
Avoid potential triggers: irritants, inhaled allergens, foods, stress
Topical Moisturizers – hydration!
- Bathe → gently pat dry skin → apply moisturizer on wet skin
Topical Steroids – anti-inflammatory!
- Apply to active affected areas of rash
- May have side effect of skin thinning
- Recommend NOT using on face, groin area, or underarms
Topical Immunomodulators – anti-inflammatory (second-line)
- May be used on face and eyelids
Antihistamines may promote sleep, but AVOID topical antihistamines as they
can actually worsen the rash
Wet-Wrap Therapy
- Soak skin in warm water for 15-20 mins → pat dry → apply topical meds on rash → apply wet dressing on top of rash → apply dry wrap over wet dressing → wrap for 2-6 hrs
- Should be individualized and should be done under close supervision of an Allergist/Immunologist
Blog post based on Med-Peds Forum talk by Ashley Nguyen, PGY2