Atopic dermatitis

Disease Description (Causes and Symptoms)

• Definition: Atopic dermatitis is a chronic, recurrent inflammatory skin disease characterized by severe itching and impaired skin barrier function. It commonly begins in childhood, and in some people it persists into adulthood.
• Causes and pathophysiology: Genetic predisposition (family history), skin barrier defects (e.g., filaggrin deficiency), immunologic abnormalities (Th2-dominant response and increased IgE), and environmental factors (allergens, air pollution, changes in dietary habits, etc.) act together. The itch → scratching → skin damage → worsening inflammation and infection cycle is the key mechanism.
• Main symptoms: Severe itching (especially at night), dryness, scaling, lichenification (thickening of the skin), erythema, vesicles, and exudation (during acute phases); the locations of eczematous lesions vary by age (infants: face, scalp, and trunk; children: flexural areas such as the arms and behind the knees; adults: hands, neck, arms, and legs, etc.).

Treatment Methods and Precautions

• Basic principles: Elimination of triggers, moisturizing the skin and restoring the skin barrier, and controlling itching, inflammation, and secondary infections.
• Topical treatment
  • Moisturizers (emollients): Apply generously several times a day (application immediately after bathing is important).
  • Topical corticosteroids: Essential for controlling acute inflammation. Adjust the potency and method of use according to the doctor’s instructions (be aware of side effects such as skin atrophy with long-term or extensive use).
  • Topical calcineurin inhibitors (tacrolimus, pimecrolimus): Used on the face and flexural areas or as an alternative for long-term therapy.
• Systemic treatment (severe or refractory cases)
  • Immunosuppressants such as cyclosporine, methotrexate, azathioprine, and mycophenolate (monitoring required: blood pressure, kidney function, liver function, blood tests, etc.).
  • Biologics: Dupilumab (IL-4/IL-13 inhibitor) — effective for moderate-to-severe chronic atopic dermatitis.
  • JAK inhibitors (e.g., upadacitinib, abrocitinib, etc.): Recently used for moderate-to-severe atopic dermatitis in adults; monitoring is necessary in consideration of risks such as thrombosis, infection, and increased lipid levels.
  • Phototherapy (especially NB-UVB): May be considered instead of or alongside systemic medications.
• Treatment of infections
  • Secondary bacterial infections (such as Staphylococcus aureus): Appropriate topical or systemic antibiotics.
  • Antiviral agents for viral infections such as herpes simplex.
• Adjunctive therapies
  • Antihistamines (for the purpose of relieving itching, improving sleep, etc.), wet wraps (wet-wrap therapy), and others.
• Precautions and risk of complications
  • Long-term use of high-potency topical steroids may cause skin atrophy, pigment abnormalities, and dilation of blood vessels. Apply the minimum effective dose, alternating the application sites.
  • Monitoring for infection and liver, kidney, and blood abnormalities is necessary when using systemic immunosuppressants or biologics.
  • Eye complications (such as atopic conjunctivitis and cataracts) may occur; evaluation is necessary if ocular symptoms develop.
  • Treatment is determined individually according to factors such as age, lesion location, severity, and accompanying allergies, so consultation with a specialist is recommended.

Checklist Before an Outpatient Visit (Preparation and Tests)

• Items to bring or prepare
  • A list of all medications and supplements currently being taken (including dosage and dosing intervals).
  • Records of previous treatments (product names, duration of use, effects, and side effects).
  • Recent blood or skin test results, if available.
  • Photos of symptoms (especially when a rash is present), and a diary of itching, redness, worsening, and improvement (when and after which factors symptoms worsened).
  • Family history (atopic dermatitis, asthma, allergic rhinitis, etc.) and personal allergy history (food and medications).
  • Information about lifestyle (occupation, pets, home environment, cosmetics and detergents used).
  • Whether pregnancy is possible (women); for children, information about breastfeeding and the infant’s or young child’s diet.
• Items the doctor may ask about during the visit
  • When symptoms began and their course (patterns of worsening and improvement).
  • The severity of itching (whether it interferes with sleep), and the distribution and changes of the rash.
  • Recently used treatments and responses, and previous medication side effects.
  • Whether there have been recent infections (fever, impetigo, etc.).

Examples of General Questions to Ask the Doctor

• What are the main side effects of this medication, and when should they be reported?
• How do you determine whether my (or my child’s) symptoms are moderate or severe?
• What ingredients should a moisturizer contain, and how many times a day and how should it be applied?
• What is the safe method of using topical steroids (potency, duration, and application site)?
• Are biologics (dupilumab) or JAK inhibitors appropriate in my case? Are tests or monitoring necessary?

Examples of Condition-Specific Questions

• In a child’s case, what tests are needed to determine whether a food allergy is causing worsening atopic dermatitis, and when is dietary restriction recommended?
• If there are recurrent skin infections (e.g., impetigo), what measures should be taken for prevention? (e.g., cleansing methods, use of topical antimicrobials, etc.)

End.