Define eczema.

Definition of Eczema

Eczema is a general term encompassing various inflammatory skin disorders that result in dry, itchy, and bumpy skin. The underlying issue is often a compromised skin barrier, which is crucial for retaining moisture and protecting against environmental aggressors. This weakened barrier leads to increased water loss and allows irritants and allergens to penetrate the skin more easily, triggering an immune response that causes inflammation.

Key Symptoms of Eczema

The clinical presentation of eczema can vary but commonly includes:

• Intense Itching (Pruritus): Often the most prominent and distressing symptom, leading to scratching that can further damage the skin.
• Dry and Cracked Skin: The skin loses moisture, becoming flaky, scaly, and sometimes developing painful cracks.
• Redness and Inflammation: Affected areas appear red, pink, or even purple/gray in darker skin tones, often swollen.
• Rashes and Bumps: Formation of skin rashes, sometimes with small, raised bumps or fluid-filled blisters that may ooze and crust over.
• Thickened, Leathery Patches (Lichenification): Chronic scratching can lead to the skin becoming thick and leathery.
• Discoloration: Post-inflammatory hypo- or hyperpigmentation, where the skin becomes lighter or darker after the rash heals, is common, especially in individuals with brown or black skin.

Causes and Risk Factors

The exact cause of eczema is often multifactorial, involving a complex interplay of genetic, environmental, and immunological factors.

• Genetic Predisposition: Individuals with a family history of eczema, asthma, or allergic rhinitis (hay fever) are at a higher risk. Specific gene variations affecting the skin's barrier function have been identified.
• Immune System Dysfunction: The immune system in individuals with eczema tends to overreact to minor irritants or allergens, triggering an inflammatory response.
• Environmental Triggers: Exposure to certain substances can provoke or worsen eczema flare-ups. These include:
  • Irritants: Soaps, detergents, harsh chemicals, perfumes, certain fabrics (e.g., wool).
  • Allergens: Dust mites, pet dander, pollen, certain foods.
  • Climate: Dry weather, extreme temperatures, humidity changes.
  • Pollutants: Smoke, air pollution.
• Emotional Stress: While not a direct cause, stress can exacerbate eczema symptoms and trigger flare-ups.

Types of Eczema

Eczema is an umbrella term for several distinct conditions. The seven main types include:

Type of Eczema	Description and Key Characteristics
Atopic Dermatitis	The most common and chronic form, often starting in infancy. Characterized by intensely itchy, dry patches that can crack, ooze, or crust. It's strongly linked to a family history of allergies and asthma (the "atopic march").
Contact Dermatitis	Results from skin contact with an irritant (irritant contact dermatitis) or an allergen (allergic contact dermatitis). Symptoms appear at the site of contact and can range from redness to blistering and burning.
Dyshidrotic Eczema	Affects the palms, soles, and sides of fingers/toes, characterized by small, intensely itchy, fluid-filled blisters. Can lead to painful cracks.
Neurodermatitis	Causes localized, intensely itchy, scaly patches on specific areas like the head, forearms, wrists, or lower legs, often due to habitual scratching of a particular spot.
Nummular Eczema (Discoid Eczema)	Presents as distinct, coin-shaped or oval lesions that are often itchy, scaly, or crusty. Commonly found on the arms and legs.
Seborrheic Dermatitis	Primarily affects areas with a high concentration of oil glands, such as the scalp, face (e.g., sides of the nose, eyebrows), and chest. Causes flaky skin, redness, and yellowish scales (e.g., dandruff in adults, cradle cap in infants).
Stasis Dermatitis	Occurs on the lower legs due to poor circulation, often in older adults. Symptoms include discolored skin, itching, swelling, and sometimes ulcers.

Treatment and Management

While there is no definitive cure for eczema, various treatments and management strategies focus on controlling symptoms, preventing flare-ups, and repairing the skin barrier.

• Moisturizers (Emollients): Regular and liberal application of gentle, fragrance-free moisturizers is crucial to hydrate the skin and restore its barrier function.
• Topical Medications:
  • Corticosteroid Creams/Ointments: Anti-inflammatory drugs applied directly to the skin to reduce redness and itching. Available in varying strengths.
  • Calcineurin Inhibitors (e.g., Tacrolimus, Pimecrolimus): Non-steroidal medications that suppress the immune system in the skin, reducing inflammation and preventing flares, particularly useful for sensitive areas.
  • Topical JAK Inhibitors and PDE4 Inhibitors: Newer topical treatments approved for eczema.
• Oral Medications:
  • Antihistamines: Can help relieve itching, especially sedating types for nighttime use to improve sleep.
  • Systemic Corticosteroids: Used for severe flare-ups but generally for short periods due to potential side effects.
  • Immunosuppressants (e.g., Cyclosporine, Methotrexate): For severe cases unresponsive to other treatments, requiring careful monitoring.
  • Biologics (e.g., Dupilumab, Tralokinumab): Injectable medications that target specific immune pathways responsible for inflammation, used for moderate to severe atopic dermatitis.
• Phototherapy (Light Therapy): Controlled exposure to ultraviolet (UV) light can help reduce inflammation and itching in some cases of moderate to severe eczema.
• Lifestyle and Home Remedies:
  • Avoiding known triggers (irritants, allergens, harsh soaps).
  • Taking lukewarm baths and applying moisturizer immediately afterward.
  • Wearing loose-fitting clothing made of natural fabrics like cotton.
  • Managing stress through relaxation techniques.
  • Using humidifiers in dry environments.
• Addressing Infections: Antibiotics or antifungals may be prescribed if secondary bacterial or fungal infections occur due to broken skin from scratching.