Overview
Definition:
Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease characterized by intense pruritus, eczematous lesions, and a tendency to occur in individuals with a personal or family history of atopy (asthma, allergic rhinitis, food allergy)
It is a complex disorder influenced by genetic, immune, and environmental factors.
Epidemiology:
AD is the most common chronic inflammatory skin disease in childhood, affecting 15-20% of children worldwide
Prevalence varies by geographic region and socioeconomic status, with higher rates reported in developed countries
It often begins in infancy or early childhood, with a significant proportion of patients experiencing remission in adolescence, though a subset continues to have disease into adulthood.
Clinical Significance:
AD significantly impacts a child's quality of life, leading to sleep disturbances, behavioral problems, and psychosocial distress
Severe AD can be debilitating, requiring intensive management and posing a burden on healthcare systems
Understanding its management, particularly step-up therapy and adjunctive measures like wet wraps, is crucial for pediatric residents preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Intense itching (pruritus) is the hallmark symptom, often worse at night
Dry skin (xerosis) is common
The distribution of lesions varies with age: in infants, it typically involves the face, scalp, and extensor surfaces
in older children and adolescents, it predominantly affects flexural areas (antecubital and popliteal fossae), neck, wrists, and ankles
Lesions can be acute (erythematous, papular, vesicular, weeping) or chronic (lichenified, hyperkeratotic).
Signs:
Erythema, papules, vesicles, scaling, lichenification, excoriations, and secondary infections (e.g., impetiginization with Staphylococcus aureus) are common findings
In chronic AD, skin thickening (lichenification) due to persistent scratching is characteristic
Dennie-Morgan lines (infraorbital folds) and hyperlinear palmar creases may be present
Pallor of the face and periorbital darkening are also observed.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the Hanifin and Rajka criteria or the UK Working Party criteria
Key features include: itchy skin plus three or more of the following: onset before age 2 years
flexural dermatitis
generally dry skin
personal history of other atopic diseases
or family history of atopic diseases
Severity can be assessed using tools like the SCORAD (Scoring Atopic Dermatitis) index.
Diagnostic Approach
History Taking:
Detailed history is essential, focusing on onset and duration of symptoms, triggers (allergens, irritants, stress), associated allergic conditions (asthma, allergic rhinitis, food allergies), previous treatments and response, and impact on quality of life
Family history of atopy is crucial
Red flags include sudden onset of severe symptoms, widespread pustulation, or signs of systemic illness, suggesting secondary infection or other differential diagnoses.
Physical Examination:
A thorough skin examination is performed, noting the morphology, distribution, and severity of lesions
Assess for signs of excoriation, lichenification, xerosis, and secondary infection
Examination of the entire skin surface, including scalp, nails, and mucous membranes, is important
General examination to assess for signs of systemic involvement or comorbidities is also warranted.
Investigations:
Routine investigations are usually not required for diagnosis
However, if secondary infection is suspected, a bacterial swab for culture and sensitivity may be performed
Allergy testing (skin prick tests or specific IgE blood tests) may be considered in select cases to identify triggers, but should not be the primary diagnostic tool
Eosinophilia may be present on complete blood count
Patch testing can be useful for contact dermatitis if suspected.
Differential Diagnosis:
Important differentials include: infantile seborrheic dermatitis, allergic contact dermatitis, irritant contact dermatitis, pityriasis rosea, scabies, tinea corporis, and cutaneous lymphoma
Differentiating AD from these conditions based on characteristic lesion distribution, morphology, and history is key for accurate management.
Management
Initial Management:
The cornerstone of AD management involves: 1
Skin barrier repair: frequent use of emollients
2
Control of inflammation: topical corticosteroids
3
Itch control: antihistamines
4
Avoidance of triggers: irritants, allergens
Education of parents/caregivers about the chronic nature of AD and management strategies is paramount.
Step Up Therapy:
Step-up therapy is employed when basic management is insufficient
This involves escalating treatment intensity based on disease severity
Options include: increased potency or frequency of topical corticosteroids
addition of topical calcineurin inhibitors (tacrolimus, pimecrolimus) for sensitive areas or as steroid-sparing agents
phototherapy (UVB) for older children
systemic immunosuppressants (e.g., cyclosporine, methotrexate) for severe, refractory AD
and biologic agents (e.g., dupilumab) for moderate-to-severe AD
Oral corticosteroids are generally avoided for long-term use due to side effects.
Wet Wraps Therapy:
Wet wrap therapy is an effective adjunctive treatment for moderate-to-severe AD flares, especially when skin is acutely inflamed, weeping, or excoriated
It involves applying emollients and/or topical corticosteroids to affected areas, followed by a layer of damp gauze or cotton bandages, and then a dry outer layer
The wraps are typically left on for several hours or overnight
This method hydrates the skin, reduces itching and inflammation, and enhances the penetration of topical medications
It should be applied under medical supervision, particularly in infants, to prevent hypothermia and monitor for infection.
Supportive Care:
Adequate hydration, appropriate clothing (loose-fitting, cotton fabrics), and stress management are important supportive measures
Nutritional assessment is vital, as food allergies can be a trigger for AD in some children
Antenatal counseling and early management of AD in infants can potentially influence disease trajectory.
Complications
Early Complications:
Secondary bacterial infections (impetiginization, cellulitis, folliculitis), primarily by Staphylococcus aureus, leading to increased inflammation, pustulation, and fever
Viral infections, such as herpes simplex virus (eczema herpeticum), can cause widespread, painful vesicular lesions and systemic illness.
Late Complications:
Chronic lichenification and skin thickening
Permanent pigmentary changes (hypo- or hyperpigmentation)
Psychological distress, sleep deprivation, social isolation, and impaired school performance
Increased risk of ocular complications like cataracts and keratoconus.
Prevention Strategies:
Early recognition and prompt treatment of secondary infections
Diligent use of emollients to maintain skin barrier integrity
Strict avoidance of known irritants and allergens
Appropriate use of topical corticosteroids and other anti-inflammatory agents
Patient and caregiver education on recognizing and managing flares and preventing complications.
Prognosis
Factors Affecting Prognosis:
Early onset, severity of disease, presence of food allergies, and family history of atopy are associated with a poorer prognosis
However, with consistent and appropriate management, many children experience significant improvement or remission by adolescence.
Outcomes:
The majority of children with AD will experience improvement over time
Moderate-to-severe cases may require ongoing management into adulthood
Effective control of inflammation and pruritus leads to improved quality of life and reduced risk of complications
Novel therapies are continuously improving outcomes for refractory cases.
Follow Up:
Regular follow-up with a dermatologist or pediatrician is crucial for monitoring disease activity, adjusting treatment regimens, and reinforcing management strategies
Educating families on recognizing early signs of flares and infections enables timely intervention
Long-term follow-up helps prevent chronic complications and manage comorbidities.
Key Points
Exam Focus:
Atopic dermatitis is a common pediatric condition
understand its pathophysiology, diagnostic criteria (Hanifin & Rajka), and age-specific distributions
Differentiate it from other eczematous conditions
Emphasize the stepwise approach to management: emollients, topical steroids, topical calcineurin inhibitors, and systemic agents (immunosuppressants, biologics)
Wet wrap therapy is a key adjunctive treatment for flares
Recognize complications like eczema herpeticum.
Clinical Pearls:
"Itch-scratch cycle" is central to AD pathogenesis
breaking this cycle with emollients and anti-pruritics is vital
Use the least potent topical corticosteroid that is effective
Reserve potent steroids for short durations on thicker skin areas
Topical calcineurin inhibitors are excellent for face and intertriginous areas
Educate parents on trigger avoidance and consistent emollient use – it's as important as medication
Wet wraps are highly effective for acute flares but require careful instruction and supervision.
Common Mistakes:
Underestimating the severity of pruritus and its impact on quality of life
Inadequate use of emollients, which are the foundation of AD care
Over-reliance on systemic treatments without optimizing topical therapy and trigger avoidance
Prescribing potent topical steroids for prolonged periods on thin skin without supervision
Misdiagnosing secondary infections or using incorrect antibiotic regimens
Neglecting the psychosocial impact of AD on the child and family.