The Department of Dermatology is a medical specialty dedicated to the diagnosis and treatment of skin, mucous membrane, hair, nail disorders and related immune diseases. Eczema, urticaria and atopic dermatitis that you mentioned are the most common allergic or inflammatory skin diseases in dermatology, with a wide range of impacts, and they have a high incidence especially in children and people with an allergic constitution.

? I. Introduction to the Department of Dermatology

Department Name: Department of Dermatology (also known as Department of Dermatology and Venereology)
Core Responsibilities: Diagnosing and treating various skin diseases, sexually transmitted diseases, skin tumors, cosmetic problems (e.g., acne, pigmentation spots) and immune-related skin diseases.

✅ Common Scope of Diagnosis and Treatment:

• Infectious skin diseases: Acne, fungal infections (tinea pedis), warts, herpes zoster

• Allergic/inflammatory skin diseases: Eczema, urticaria, atopic dermatitis, contact dermatitis

• Autoimmune skin diseases: Lupus erythematosus, pemphigus

• Neoplastic skin diseases: Skin cancer, pigmented nevi

• Hair and nail diseases: Alopecia, onychomycosis

• Medical aesthetic services: Laser therapy, glycolic acid peels, injectable aesthetics

? II. Eczema

? Definition:

Eczema is a broad term referring to a group of chronic inflammatory skin diseases characterized by dry skin, pruritus, erythema, papules, exudation and desquamation. It can occur at any age and on any part of the body.

? Common Types:

• Acute eczema: Erythema and swelling, blisters, exudation

• Subacute eczema: Erythema, crusting, desquamation

• Chronic eczema: Skin thickening, roughness, hyperpigmentation

? Common Triggers:

• Allergens (dust mites, pollen, food)

• Irritants (detergents, fragrances, metals)

• Dry climate, excessive sweating

• Mental stress, decreased immunity

? Commonly Affected Areas:

Hands, cubital fossae, popliteal fossae, face, neck

 III. Urticaria

? Definition:

Commonly known as hives, urticaria is a sudden, transient, severely pruritic edematous skin reaction, manifested as well-demarcated erythematous or pale wheals. The lesions usually resolve spontaneously within 24 hours but may recur repeatedly.

? Classification:

? Typical Manifestations:

• Sudden pruritus → Erythematous and edematous wheals appearing on the skin

• Wheals vary in size and shape, and may coalesce into plaques

• Resolve spontaneously within 24 hours without leaving scars, with new lesions emerging continuously

• Severe cases may be accompanied by angioedema (swelling of the eyelids, lips and throat)

? Common Triggers:

• Food (seafood, nuts, eggs)

• Medications (antibiotics, analgesics)

• Infections (viral, bacterial)

• Insect bites

• Physical stimuli (cold, heat, sunlight, pressure)

• Autoimmune factors (common in chronic urticaria)

IV. Atopic Dermatitis (AD)

? Definition:

Atopic Dermatitis (AD) is a chronic, recurrent, pruritic and inflammatory skin disease, which is a component of the atopic diathesis. It often coexists with allergic rhinitis and asthma, and is regarded as the starting point of the Atopic March.

✅ Atopic Diathesis: A genetic predisposition that makes an individual susceptible to allergic diseases.

? Three Core Characteristics:

1. Chronic pruritus

2. Typical skin lesions and distribution patterns

3. Personal or family history of allergies (e.g., asthma, rhinitis)个人或家族过敏史（如哮喘、鼻炎）

? Manifestations in Different Age Groups:

? Core Issues:

• Impaired skin barrier function (e.g., filaggrin gene mutation)

• Excessive immune system response

• Microbial dysbiosis (e.g., Staphylococcus aureus colonization)

? V. How to Distinguish Between the Three?

? Simple Mnemonics:

• Urticaria:Onset fast, resolution fast, intense itching

• Eczema: Recurrent rashes, dry skin, easy to break

• Atopic Dermatitis: Onset in early childhood, itching severe enough to disrupt sleep, family history of allergies

? VI. Treatment Methods

1. Basic Treatment: Skin Barrier Repair

• Daily moisturization: Use fragrance-free, non-irritating moisturizers (e.g., Vaseline, CeraVe, Aveeno)

• Gentle cleansing: Avoid hot water scrubbing, minimize soap use

• Avoid scratching: Keep nails short and wear cotton clothing

2. Pharmacological Therapy

3. Identify Triggers

• Undergo allergen testing (IgE testing, skin prick testing)

• Keep a food diary (if food allergy is suspected)

• Avoid contact with known allergens

4. Biologics (Novel Therapy)

• Dupilumab (Dupixent): Indicated for atopic dermatitis and asthma, exerts a significant effect by targeted inhibition of inflammatory pathways.

• Omalizumab: Indicated for chronic urticaria and allergic asthma.

? VII. When to Consult a Dermatologist?

Seek medical attention promptly if you or a family member experience the following conditions:

• Recurrent skin pruritus and rashes that disrupt sleep

• Erythema and exudation on an infant’s face with suspected atopic dermatitis

• Sudden onset of wheals with recurrent episodes for more than 6 weeks

• Refractory eczema with skin thickening and fissures

• The need for definitive allergen identification and standardized treatment

✅ Summary

? Warm Reminder:

• Do not use potent glucocorticoid ointments for a long time without medical supervision; their use must be under the guidance of a doctor.

• Eczema is not caused by "moisture", but by impaired skin barrier function — the drier the skin, the more likely an outbreak is to occur.

• Atopic dermatitis is the starting point of the "atopic march"; early intervention can reduce the risk of developing asthma and rhinitis in the future.

If you experience related symptoms, it is recommended to consult a dermatologist or allergologist as early as possible. With scientific management, you can bid farewell to the distress of pruritus!