Dermatitis

Disease Description (Causes and Symptoms)

• Definition: A general term for inflammatory reactions of the skin, used synonymously with eczema. The interaction between the epidermis and dermis, skin barrier dysfunction, and changes in immune responses are the main pathophysiological mechanisms.
• Causes: There are several types, and the causes vary.
  • Atopic: Genetic skin barrier defects and immune imbalance (mainly Th2)
  • Contact (irritant·allergic): Exposure to physical or chemical irritants or antigens (delayed hypersensitivity [type IV])
  • Seborrheic, xerotic (age·environmental factors), chemical or occupational exposure, etc.
• Summary of pathophysiology: Skin barrier (stratum corneum) damage → increased water loss · easier antigen penetration → local inflammation and immune cell activation → erythema·vesicles in the acute phase, vesicles·exudation in the subacute phase, and dryness·thickening (lichenification)·pigment changes in the chronic phase
• Main symptoms: Severe itching, erythema, papules, vesicles (blisters), exudate, cracking·dryness·scaling, and, over time, lichenification (thickening of the skin) and pigment changes
• Aggravating factors: Irritating detergents·soaps, excessive handwashing, stress, climate (dryness·cold·high temperatures), allergen contact, and infection (bacterial·fungal)

Treatment Methods

• Basic principles: Restore the skin barrier (moisturization) + control inflammation + avoid triggers
• Topical treatment
  • Moisturizers (main treatment): Use products free of fragrances·irritants and apply frequently and sufficiently
  • Topical corticosteroids: Relieve inflammation·itching; select the formulation and potency according to the location·severity of the lesions. Take precautions against skin atrophy and other effects when used long-term or on sensitive areas
  • Topical calcineurin inhibitors (tacrolimus·pimecrolimus): Alternatives for the face·skin folds or when long-term corticosteroid use should be avoided
• Systemic treatment (for severe or extensive cases)
  • Oral corticosteroids (for short-term use during acute exacerbations), immunosuppressants (cyclosporine, methotrexate, azathioprine, etc.) — specialist assessment required
  • Biologics: Dupilumab and others may be used for moderate to severe atopic dermatitis (confirm the indication)
• Phototherapy: Symptoms may be improved with narrow-band UVB and similar treatments
• Infection treatment: Antibiotics may be used when secondary bacterial infection (such as Staphylococcus aureus) is suspected; antifungal agents are used for conditions such as seborrheic dermatitis
• Lifestyle management
  • Avoid irritating products (including fragrances·alcohol), take short showers with lukewarm water, and use mildly irritating detergent when washing clothes
  • Use moisturizers regularly and humidify indoor air (avoid dry environments)
  • Use protective equipment (such as cotton gloves) when there is occupational exposure involving the hands·feet or other areas
• Precautions: Long-term·extensive use of topical corticosteroids may cause skin atrophy·telangiectasia·pigment changes and other effects, so consult a doctor about the choice of medication and duration of use

Checklist Before an Outpatient Visit (Including Example Questions)

• Items to prepare
  • List of currently used medications·ointments (including prescription·OTC products)
  • Records of previous treatments and their effects (which ointments·medications were used and how the condition responded)
  • Notes on when symptoms began·their course and factors that worsen·improve them
  • Photos of the affected areas (photos taken especially early in the illness can be useful)
  • Past medical history (asthma·allergic rhinitis·history of atopy, occupational history) and family history
  • Recent exposures (new cosmetics·detergents·workplace environment·pets, etc.)
  • Bring previous test results, if available (dermatology patch tests·skin biopsies·blood tests, etc.)
• Items to tell the doctor in advance during the outpatient visit
  • Whether the symptoms involve severe itching·sleep disturbance
  • The impact of the symptoms on daily life·work
  • Whether you are pregnant·breastfeeding (affects medication selection)

Example questions (items for patients to organize before the outpatient visit)

• "When did the symptoms begin, and in what situations do they worsen?"
• "What ointments or moisturizers am I currently using, and how effective have they been?"

Examples of General Questions to Ask the Doctor

• "What are the expected effects and side effects of this medication (or ointment)?"
• "How should I use topical corticosteroids safely (potency·duration·frequency)?"
• "Are additional tests (patch test, skin biopsy, blood test, etc.) necessary for my current condition?"
• "How long is it expected to take for the symptoms to improve, and how likely are they to recur?"
• "Should I visit the hospital immediately if an infection is suspected? What symptoms indicate an infection?"

Examples of Condition-Specific Questions

• "How can you distinguish whether these symptoms are allergic contact dermatitis or irritant contact dermatitis? Is a patch test necessary?"
• "My chronic itching (including sleep disruption) is severe. Could you explain the indications and expected effects of biologic treatment such as dupilumab?"