Infant AD → food allergy → asthma → allergic rhinitis is the well-known "atopic march". Early aggressive treatment of atopic dermatitis and skin-barrier repair can reduce later asthma and food-allergy risk by up to 30%.Adult atopic dermatitis significantly correlates with cardiovascular disease, depression, and suicidal ideation — not just "itchy skin", but systemic inflammation requiring long-term monitoring for comorbidities.
The atopic march
Infant AD → food allergy (1-3y) → asthma (3-7y) → allergic rhinitis (school age). Skin-barrier disruption allows allergen sensitization through the skin. Daily infant moisturizer reduces AD development by ~50%; early peanut/egg introduction (4-11 months, with allergy assessment) prevents food allergy (LEAP, EAT trials).
Seven essential comorbidity screens
- Asthma + allergic rhinitis (atopic triad — 30-66%)
- Food allergy (10-30% in children) — diagnose by symptom-triggered history; do not screen all foods by IgE
- Eosinophilic esophagitis — 2-4× risk; dysphagia, food impaction
- Depression / anxiety / suicidality — OR 1.4-2.0; PHQ-2/GAD-2 yearly
- Cardiovascular disease (adults) — moderate-severe AD MI/stroke ↑ 1.2-1.5×
- Infections: S. aureus (80-90% colonization), eczema herpeticum (HSV — emergency, IV acyclovir), eczema coxsackium, molluscum, verruca, tinea
- Ocular: atopic keratoconjunctivitis, keratoconus (from eye-rubbing), anterior subcapsular cataract; dupilumab-conjunctivitis 8-15%
Pregnancy
60% improve, 20% unchanged, 20% worsen. Safe: moisturizer, low-mid TCS (limited area), NB-UVB. Avoid: methotrexate, MMF, acitretin, JAK inhibitors. Limited data for biologics — mAbs theoretically transferred via placenta; certolizumab is the model "no Fc" example for psoriasis but no FDA-approved AD biologic has clear pregnancy positioning yet.
Infants and young children (0-5 years)
Daily moisturizer always; hydrocortisone 1% as first-line topical steroid; tacrolimus 0.03% ≥ 2 y; crisaborole 2% ≥ 3 months; dupilumab ≥ 6 months. Avoid super-potent steroids, JAKi (< 12 y), PUVA, chronic systemic steroids. Educate on early allergen introduction.
Elderly
Differential: seborrheic, stasis, drug eruption, CTCL, scabies, lymphoma. Avoid JAKi (≥ 65 y is black-box high-risk); prefer dupilumab/tralokinumab/lebrikizumab.
Refractory AD
Re-evaluate diagnosis (rule out CTCL, scabies, contact dermatitis, psoriasis overlap), biopsy if needed, address triggers (S. aureus, allergens, occupation), switch mechanism (dupilumab → upadacitinib; IL-13 → IL-31R), combine treatments, multidisciplinary referral.
Bottom line
AD is systemic Th2 inflammation. Annual screening for atopic march, comorbidities, mental health, infections, and ocular findings reduces respiratory, cardiovascular, and psychiatric morbidity. Each patient demographic — infants, pregnant, elderly, refractory — has tailored evidence-based care.