# Atopic Dermatitis in Children: Practical Management

## Introduction

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease of childhood, affecting up to 20% of children in developed countries. It typically presents in the first year of life, profoundly impacts quality of life for both child and family, and serves as the initial step in the "atopic march." Effective management requires a systematic approach combining skin barrier restoration, anti-inflammatory therapy, and trigger avoidance.

## Epidemiology and Natural History

Sixty percent of AD cases develop by age 1, and 85% by age 5. Approximately 70% of childhood AD clears by adolescence, though many patients retain sensitive, dry skin or develop other atopic conditions. The **atopic march** describes the progression from AD to food allergies (30%), allergic rhinitis (50%), and asthma (30%). Prevalence has increased two- to three-fold over the past 30 years, particularly in industrialized nations, consistent with the **hygiene hypothesis**.

## Pathogenesis

### Barrier Dysfunction

**Filaggrin (FLG) mutations** are the strongest known genetic risk factor for AD, present in approximately 30% of patients. Defective filaggrin leads to an impaired cornified envelope, reduced natural moisturizing factor (NMF), and elevated transepidermal water loss (TEWL). Decreased **ceramide** levels in the stratum corneum further compromise barrier integrity. This barrier disruption facilitates allergen penetration and microbial colonization.

### Immune Dysregulation

Acute AD is characterized by a **Th2-dominant immune response** with elevated IL-4, IL-13, IL-31 (a key pruritus mediator), IL-5, and TSLP. Chronic AD lesions show a mixed Th2/Th1/Th22 polarization. **IgE hyperproduction** is driven by IL-4/IL-13 signaling, and reduced **antimicrobial peptides** (LL-37, beta-defensins) predispose to infections.

### The Itch-Scratch Cycle

**IL-31** is a key pruritogen that acts through IL-31 receptor A on sensory neurons. TSLP, IL-4, and IL-13 also contribute to neurogenic itch. Scratching damages the barrier and releases alarmins (TSLP, IL-33), which amplify Th2 inflammation, perpetuating a vicious cycle.

## Clinical Features by Age

### Infantile AD (0-2 years)

Infantile AD presents with erythematous, exudative, crusted patches on the **cheeks**, scalp, and extensor extremities. The **diaper area is typically spared**, which serves as an important diagnostic clue. Generalized xerosis is present.

### Childhood AD (2-12 years)

The distribution shifts to a classic **flexural pattern**, affecting the antecubital and popliteal fossae, wrists, ankles, and neck. Lichenification from chronic rubbing becomes prominent. Periorbital darkening (**allergic shiners**) and Dennie-Morgan infraorbital folds may be observed.

### Adolescent/Adult AD

Flexural involvement persists, and the eruption may also affect the hands, eyelids, and head and neck. Lichenified, excoriated plaques and prurigo nodularis-like lesions may develop.

<image>Clinical photographs showing age-dependent distribution of atopic dermatitis: infantile AD with facial and extensor involvement, childhood AD with flexural lichenification, and adolescent AD with hand eczema and eyelid dermatitis</image>

## Diagnosis

The diagnosis is primarily clinical. The **Hanifin and Rajka criteria** (4 major plus 3 minor criteria) remain the standard. Major criteria include pruritus, typical morphology and distribution, a chronic or relapsing course, and a personal or family history of atopy. There is no pathognomonic laboratory test; elevated serum IgE supports the diagnosis but is not required. Biopsy is rarely needed and shows spongiotic dermatitis in acute disease or psoriasiform hyperplasia with spongiosis in chronic disease. Severity assessment tools such as SCORAD, EASI, and IGA are important for treatment decisions and clinical trial enrollment.

## Management: Stepwise Approach

### Step 1: Baseline Therapy (All Patients)

**Emollient therapy** is the foundation and should be applied liberally and frequently (minimum twice daily), especially after bathing. The **"soak and seal" technique** involves a lukewarm bath for 5 to 10 minutes followed by immediate application of emollient to damp skin. Products should be fragrance-free and dye-free; ceramide-containing moisturizers may provide additional benefit. **Trigger avoidance** includes identifying and minimizing contact with irritants (wool, harsh soaps), environmental allergens, and emotional stressors. Maintaining comfortable ambient temperature and humidity is also helpful.

### Step 2: Topical Anti-Inflammatory Therapy

**Topical corticosteroids (TCS)** remain first-line anti-inflammatory agents. Low-potency formulations (hydrocortisone 2.5%) are appropriate for the face, intertriginous areas, and infants, while medium-potency formulations (triamcinolone 0.1%) are used for the trunk and extremities. **Proactive therapy** with twice-weekly application to previously affected areas reduces flare frequency by approximately 50%. Addressing **steroid phobia** is essential, as underdosing is the most common cause of treatment failure. **Topical calcineurin inhibitors** (tacrolimus 0.03%/0.1%, pimecrolimus 1%) are steroid-sparing agents preferred for the face, eyelids, and intertriginous areas. They carry no risk of skin atrophy, and the FDA black box warning regarding lymphoma risk is not supported by long-term safety data. **Crisaborole 2% ointment**, a topical PDE4 inhibitor, is approved for mild-to-moderate AD in patients aged 3 months and older. **Ruxolitinib 1.5% cream**, a topical JAK inhibitor, is approved for mild-to-moderate AD in patients aged 12 and older.

### Step 3: Adjunctive Therapies

**Wet wrap therapy** involves a damp layer of tubular bandage over emollient or TCS, covered by a dry layer, to enhance penetration and reduce itch. It is particularly useful for acute flares. **Bleach baths** (0.5 cup of 6% sodium hypochlorite per full bathtub, 2 to 3 times weekly) reduce **Staphylococcus aureus** colonization, which is present on over 90% of AD skin. First-generation **antihistamines** (hydroxyzine, diphenhydramine) may aid sleep through sedation but do not directly address AD-related itch, and non-sedating antihistamines have minimal efficacy for AD pruritus. Secondary infections are treated with topical mupirocin for localized impetiginization and systemic antibiotics (cephalexin, TMP-SMX) for widespread infection.

### Step 4: Phototherapy

**Narrowband UVB (NB-UVB)** is first-line phototherapy for moderate-to-severe AD in children old enough to stand in the light box. It reduces inflammation, decreases S. aureus colonization, and increases vitamin D, typically administered 2 to 3 sessions per week for 12 to 16 weeks.

### Step 5: Systemic Therapy

**Dupilumab** (anti-IL-4 receptor alpha monoclonal antibody) is FDA-approved for moderate-to-severe AD in children aged 6 months and older. It dramatically reduces EASI scores, pruritus, and flare frequency, with injection-site reactions and conjunctivitis as the main adverse effects. **Tralokinumab** (anti-IL-13) is approved for adults, with pediatric trials ongoing. **Oral JAK inhibitors** (abrocitinib and upadacitinib) are approved for adults and are highly effective for pruritus, requiring monitoring for infections, cytopenias, lipid elevations, and thromboembolic risk. Traditional immunosuppressants used off-label in children include cyclosporine (which has the most rapid onset), methotrexate, mycophenolate mofetil, and azathioprine. **Systemic corticosteroids** should be avoided in children because rebound flares are severe and frequent use leads to growth suppression and adrenal insufficiency.

| Systemic Agent | Mechanism | Age Approval | Key Monitoring | Notable AEs |
|---------------|-----------|-------------|----------------|-------------|
| Dupilumab | Anti-IL-4Rα | ≥6 months | None routine | Conjunctivitis, injection-site reactions |
| Tralokinumab | Anti-IL-13 | Adults (pediatric trials ongoing) | None routine | Injection-site reactions |
| Abrocitinib | JAK1 inhibitor | ≥12 years (adults) | CBC, lipids, LFTs | Infections, cytopenias, VTE risk |
| Upadacitinib | JAK1 inhibitor | ≥12 years (adults) | CBC, lipids, LFTs | Infections, cytopenias, VTE risk |
| Cyclosporine | Calcineurin inhibitor | Off-label (children) | BP, renal function, lipids | Nephrotoxicity, hypertension |
| Methotrexate | Antifolate | Off-label (children) | CBC, LFTs | Hepatotoxicity, myelosuppression |

<image>Stepwise treatment algorithm pyramid for pediatric atopic dermatitis showing emollients at the base, progressing through topical anti-inflammatories, phototherapy, and systemic biologics at the apex, with severity indicators at each level</image>

## Special Considerations

### Eczema Herpeticum

Eczema herpeticum is a disseminated HSV infection in AD patients, presenting as **punched-out erosions**, vesicles, and hemorrhagic crusts. It is a medical emergency requiring immediate treatment with **IV acyclovir** in severe cases or **oral valacyclovir** in mild cases. Treatment should not be delayed for culture results.

### Food Allergy and AD

Food allergy affects approximately 30% of children with moderate-to-severe AD. Common culprits include egg, milk, peanut, soy, wheat, and tree nuts. Evaluation is warranted only if there is a clear temporal relationship between food ingestion and flares. **Empiric elimination diets should not be recommended**, as they lead to nutritional deficiency without proven benefit. Referral to an allergist for structured testing (skin prick testing, specific IgE, oral food challenge) is the appropriate approach.

### Vaccination

Children with AD should receive all routine vaccinations on schedule. The **smallpox (vaccinia) vaccine** is contraindicated due to the risk of eczema vaccinatum.

<image>Clinical photograph of eczema herpeticum showing clustered punched-out erosions with hemorrhagic crusts superimposed on eczematous skin of the face in a child</image>

## Key Clinical Pearls

Emollient adherence is the single most impactful intervention. Sufficient quantities should be prescribed (250 to 500 g per week for generalized AD), and application technique should be demonstrated. Steroid phobia is the leading cause of treatment failure and should be addressed proactively at every visit. Proactive TCS application (twice weekly to prior flare sites) significantly reduces relapse rates. Dupilumab has transformed the management of moderate-to-severe pediatric AD with an excellent safety profile. Always examine for eczema herpeticum in any AD patient with a sudden, painful worsening accompanied by punched-out erosions.

## References

1. Eichenfield LF, Tom WL, Chamlin SL, et al. Guidelines of care for the management of atopic dermatitis. *J Am Acad Dermatol*. 2014;70(2):338-351.
2. Simpson EL, Bieber T, Guttman-Yassky E, et al. Two phase 3 trials of dupilumab versus placebo in atopic dermatitis. *N Engl J Med*. 2016;375(24):2335-2348.
3. Wollenberg A, Barbarot S, Bieber T, et al. Consensus-based European guidelines for treatment of atopic eczema (atopic dermatitis). *J Eur Acad Dermatol Venereol*. 2018;32(5):657-682.
4. Paller AS, Siegfried EC, Thaçi D, et al. Efficacy and safety of dupilumab in children aged 6 months to younger than 6 years with moderate-to-severe atopic dermatitis. *JAMA Dermatol*. 2023;159(6):596-605.