OFFICIAL ABP TOPIC:

Understand the clinical manifestations, diagnosis, and management of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD), or eczema, is a chronic, relapsing inflammatory skin disorder that affects 10-20% of children worldwide. Characterized by intense pruritus and eczematous lesions, AD often occurs with other atopic conditions like asthma and allergic rhinitis. Pediatricians are instrumental in accurately diagnosing and effectively managing AD to enhance patient quality of life and outcomes.

CLINICAL MANIFESTATIONS

Common features

Common features of AD include:

• Pruritus
• Xerosis (dry skin)
• Early age of onset (60% by one year of age and 85% by five years old)
• Eczematous lesions:
  • Acute episodes: erythematous papules and vesicles with crusting
  • Chronic AD: hyperpigmented lichenification (skin thickening) and fissuring
• Typical age-specific distribution patterns
  • Infants (0-2 years): Erythematous papules and vesicles on cheeks, scalp, and extensor areas, sparing the diaper area
  • Children (2-12 years): Lichenified plaques on flexural regions (antecubital and popliteal fossae), neck, and wrists
  • Adolescents: Lichenified plaques in flexural areas, face, neck, and hands
  • Chronic or relapsing disease course

DIAGNOSIS

The diagnosis of AD is typically based on clinical findings. The American Academy of Dermatology uses three sets of categories to help make the diagnosis.

Essential Features (all required):

• Pruritus
• Eczematous dermatitis with typical morphology and age-specific patterns
• Chronic or relapsing course

Important Features (at least two):

• Onset before two years of age
• Personal or family history of atopy
• Xerosis

Associated Features (at least one):

• Facial pallor, white dermographism
• Keratosis pilaris, palmar hyperlinearity, pityriasis alba
• Periorbital darkening (allergic shiners), folds under the lower eyelids
• Perioral eczema
• Periauricular fissuring
• Thinning or absence of the lateral eyebrows (Hertoghe’s sign)
• Groin or axilla spared

Severity Assessment  

• Mild: Localized areas of dry skin, occasional itching, limited erythema
• Moderate: More extensive dry skin, frequent itching, erythema with excoriation and localized skin thickening
• Severe: Widespread xerosis, near-constant itching, erythema with excoriations, extensive skin thickening, bleeding, oozing, fissuring

Laboratory Findings 

While not part of the diagnostic criteria, up to 80% of patients with AD have increased serum IgE levels, often with eosinophilia.

• IgE level tends to vary with disease severity, although some patients with severe AD have normal IgE.
• Most AD patients have cutaneous hyperreactivity to environmental stimuli, including exposure to food and inhalant allergens and irritants

MANAGEMENT

Management of AD is multifaceted:  

Maintain skin hydration

• Frequent use of emollients and moisturizers
• Lukewarm baths with mild cleansers followed by moisturizer application

Minimize exposure to exacerbating factors

• Irritants (e.g., wool clothing, harsh soaps, detergents, fragrances)
• Excessive bathing
• Allergens (when applicable)

Pharmacological interventions

Topical therapies (for mild to moderate AD):

• First line: Low-potency topical corticosteroids (e.g., hydrocortisone 2.5%, desonide 0.05%)
• Topical calcineurin inhibitors (e.g., pimecrolimus 1%, tacrolimus 0.03%)
• Medium-potency topical corticosteroids (e.g., triamcinolone 0.1%, fluocinolone 0.025%) for moderate disease
• Crisaborole (phosphodiesterase 4 inhibitor)
• Ruxolitinib (JAK inhibitor approved in children >12 years old)

Systemic therapies (for moderate-severe AD refractory to topical treatment):

• First line: Biologic agents (e.g., dupilumab, tralokinumab, lebrikizumab)
• Oral JAK inhibitors (e.g., abrocitinib, upadacitinib) for children >12 years old, in the absence of contraindications
• Immunosuppressants (e.g., cyclosporine, methotrexate, azathioprine, mycophenolate)
• Allergen immunotherapy for patients with known sensitization and AD refractory to standard therapies

Managing pruritus

• Behavioral interventions such as habit reversal training and cognitive behavioral therapy may be useful for chronic pruritus
• Pramoxine, a topical antipruritic anesthetic, is available over the counter
• Short-term sedating antihistamines (e.g., diphenhydramine, hydroxyzine) for acute flares with sleep disturbance
• Topical crisaborole decreases the production of pruritogenic cytokines
• Phototherapy, 2-3 times a week, can help treat AD and reduce pruritus

Managing superinfections

Patients with eczema are at increased risk for skin infections.

• Bacterial (typically S. aureus):
  • Localized: Topical antiseptics (e.g., dilute bleach baths) and optimized topical therapy
  • Extensive: Oral antibiotics (e.g., cephalexin, penicillinase-resistant penicillins) for 5-7 days
• Eczema herpeticum: AD infected with herpes simplex (punched-out erosions, vesicles) should be treated promptly with oral acyclovir; IV acyclovir may be needed for severe cases

REFERENCES

https://www.uptodate.com/contents/atopic-dermatitis-eczema-pathogenesis-clinical-manifestations-and-diagnosis

https://www.uptodate.com/contents/treatment-of-atopic-dermatitis-eczema/

https://publications.aap.org/pediatricsinreview/article/39/4/180/35153/Atopic-Dermatitis