Dermatology
Atopic Dermatitis
Built from Dermatology, 5th Edition

What’s inside
16 sections · 182 slides
Overview
- What this topic covers
Introduction and Definitions
What atopic dermatitis is, and how the term came to be defined
- What is atopic dermatitis
- Atopic dermatitis and the atopic family of diseases
- The atopic march
- History of the term 'atopic dermatitis'
- IgE-associated vs non-IgE-associated AD
Epidemiology
How common AD is, who gets it, and how it behaves over time
- How common is atopic dermatitis
- Disease course over time
- Three subsets by age of onset
- Early-onset AD in detail
Pathogenesis
Why atopic dermatitis happens: barrier, immune system, and skin microbes
- Three interacting mechanisms
- How the three mechanisms connect
- Genetic factors
- Candidate genes for atopic dermatitis
- Selected candidate genes for atopic dermatitis
- Selected candidate genes for atopic dermatitis (continued)
- Selected candidate genes for atopic dermatitis (continued)
- Epidermal barrier dysfunction
- Filaggrin: the single strongest AD gene
- What filaggrin mutations cause clinically
- Stratum corneum lipids
- Proteases and protease inhibitors
- Consequences of excess protease activity
- Immune dysregulation: the changing cytokine picture
- Innate and adaptive immunity together
- Thymic stromal lymphopoietin (TSLP)
- IL-4 and IL-13: the core AD cytokines
- Other cytokines: Th17, IL-26, IL-31, IL-33
- IL-31: the itch cytokine
- Innate lymphoid cells (ILCs)
- The cutaneous microbiome
- How S. aureus drives inflammation
Clinical Features by Age
How AD looks in infants, children, adults, and the elderly
- The basic lesion types
- Distribution patterns of atopic dermatitis and regional variants
- Reading the distribution map
- Papular pattern in darkly pigmented skin
- Infantile AD (under 2 years)
- Infantile AD on the face
- Infantile AD sparing the central face
- Acute infantile AD: face and extensor limbs
- Widespread infantile AD
- Infantile AD on the extensor arms
- Childhood AD (2 to 12 years)
- Flexural AD in a child
- More flexural examples: knee and elbow folds
- Antecubital fossa involvement
- Extensive AD in a child
- Childhood AD extending to the wrists and hands
- Adult and adolescent AD (over 12 years)
- Chronic AD: elbow folds, ankle, and hands
- Chronic AD: ankle papules and hand/wrist plaques
- Coalescing papules on the ankle
- Lichenified plaques across two skin phototypes
- Lichenification in a young child
- Lichenification in an adult
- Severe chronic hand involvement
- AD in the elderly (over 60 years)
- Postinflammatory hypopigmentation
- Postinflammatory depigmentation
Regional Variants
Site-specific patterns that can occur alone or alongside the classic picture
- Facial regional variants
- Atopic cheilitis and nipple eczema
- Lip-licker's eczema close-up
- AD of the scalp and forehead worsened by Malassezia
- Acral (hand and foot) variants
- Severe chronic hand eczema in an adult
- Prurigo and nummular variants
- Papular, prurigo, and nummular AD variants
Associated Cutaneous Features
Pruritus, the 'atopic stigmata', and pityriasis alba
- Pruritus: the hallmark symptom
- Excoriations from scratching
- Atopic stigmata: overview
- Atopic stigmata mapped on the body
- Atopic stigmata: full reference table
- Associated features of atopic dermatitis (“atopic stigmata”)
- Associated features of atopic dermatitis (“atopic stigmata”) (continued)
- Associated features of atopic dermatitis (“atopic stigmata”) (continued)
- Keratosis pilaris: what it is
- Keratosis pilaris: classic and rubra variants
- Keratosis pilaris: erythema and hyperpigmentation
- Keratosis pilaris with subtle background erythema
- Widespread keratosis pilaris
- Keratosis pilaris rubra: a distinct variant
- Keratosis pilaris rubra on the lateral face
- Pityriasis alba
- Pityriasis alba: clinical appearance
Complications and Extracutaneous Disease
Infections, quality of life, and disease beyond the skin
- Bacterial infection
- Superinfection with group A Streptococcus
- Infected hand dermatitis
- MRSA folliculitis of the back
- Eczema herpeticum: a viral emergency
- Eczema herpeticum: punched-out crusted erosions
- Who is most at risk of eczema herpeticum
- Impact on quality of life
- Ocular complications
- Psychiatric and cardiovascular associations
Diagnostic Criteria and Severity Scores
How AD is formally diagnosed, and how severity is measured
- Diagnosis is clinical, not lab-based
- Diagnostic features and triggers of atopic dermatitis
- Diagnostic features and triggers of atopic dermatitis (continued)
- Validated severity scoring tools
- Validated severity-scoring tools (appendix references)
Pathology
What a skin biopsy shows at each stage of AD
- Histology depends on the stage of the lesion
- Histology of acute and subacute atopic dermatitis
- What biopsy can and cannot tell you
Differential Diagnosis
What else can look like atopic dermatitis
- A broad differential diagnosis
- AD vs seborrheic dermatitis and scabies in infants
- AD vs allergic contact dermatitis and mycosis fungoides
- Protein contact dermatitis
- Causes of protein contact dermatitis
- Full differential diagnosis reference table
- Differential diagnosis of atopic dermatitis
- Differential diagnosis of atopic dermatitis (continued)
- Differential diagnosis of atopic dermatitis (continued)
- Differential diagnosis of atopic dermatitis (continued)
- Differential diagnosis of atopic dermatitis (continued)
Treatment: General Approach and Topical Therapy
From daily skin care to first-line anti-inflammatory drugs
- A proactive treatment philosophy
- Proactive management plan for atopic dermatitis
- Reading the management plan
- Education and self-management
- Bathing
- Moisturizers: the cornerstone of care
- Topical corticosteroids: first-line therapy
- Choosing the right topical corticosteroid
- Topical corticosteroid safety and 'steroid phobia'
- Topical calcineurin inhibitors (TCIs)
- TCIs: side effects and the cancer-risk debate
- Crisaborole
- Topical JAK inhibitors
- Wet wrap therapy
Treatment: Phototherapy and Systemic Therapy
Options for AD that does not respond to topical treatment alone
- Phototherapy
- Interleukin-4/-13 receptor inhibitors: dupilumab
- Dupilumab: dosing and side effects
- IL-13 inhibitors: tralokinumab and lebrikizumab
- Oral JAK inhibitors
- Oral JAK inhibitors: safety monitoring
- Conventional immunosuppressive agents
Adjunctive Therapy and Managing Coexisting Disease
Supporting treatments, plus food allergy, aeroallergens, and contact allergy
- Antimicrobials and antiseptics
- Antihistamines and melatonin
- Diet, supplements, and complementary therapies
- The therapeutic ladder for AD
- Therapeutic ladder for atopic dermatitis
- Therapeutic ladder for atopic dermatitis (continued)
- Therapeutic ladder for atopic dermatitis (continued)
- Therapeutic ladder for atopic dermatitis (continued)
- Therapeutic ladder for atopic dermatitis (continued)
- Therapeutic ladder for atopic dermatitis (continued)
- Food allergies and AD
- Working up suspected food allergy
- Aeroallergens and allergic contact dermatitis
Prevention
What has, and has not, been shown to prevent AD
- What does NOT prevent AD
- Possible but unproven prevention strategies
- Key takeaways
- The modern treatment ladder
References
Sources cited in this chapter
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- Dermatology, 5th Edition (2-Volume Set)