Unit
- Eczema definition: Eczema is an inflammatory skin condition characterized by dry, itchy, and red skin. It often begins in childhood and can persist into adulthood. The term eczema is sometimes used interchangeably with atopic dermatitis, which is the most common form. Understanding the broad category helps in identifying appropriate management strategies.
- Atopic dermatitis: This is the most prevalent type of eczema, linked to an overactive immune response to environmental triggers. It frequently coexists with asthma and hay fever, forming the atopic triad. Patients experience intense pruritus and eczematous lesions on flexural areas, face, and extensor surfaces.
- Contact dermatitis: Caused by direct skin contact with irritants or allergens. Irritant contact dermatitis results from chemical damage, while allergic contact dermatitis is a delayed hypersensitivity reaction. Common culprits include nickel, fragrances, and preservatives in personal care products.
- Seborrheic dermatitis: Affects areas rich in sebaceous glands such as the scalp, face, and chest. It presents as greasy, yellowish scales and erythema. While not always itchy, it can be uncomfortable. It is associated with Malassezia yeast overgrowth and is common in infants and adults.
- Dyshidrotic eczema: Characterized by small, deep-seated blisters on the palms, soles, and lateral fingers. The cause is unknown but linked to stress, sweat, and nickel exposure. It can be painful and recurrent, impacting daily activities.
- Nummular eczema: Presents as coin-shaped plaques of eczema, often on the trunk and extremities. It is very itchy and can be mistaken for fungal infections. Dry skin and environmental irritants can trigger flare-ups.
- Stasis dermatitis: Occurs in the lower legs due to poor venous circulation, often in older adults. It leads to swelling, redness, scaling, and ulceration. Management focuses on compression and leg elevation in addition to topical therapy.
- Prevalence and impact: Eczema affects up to 20% of children and 3% of adults worldwide. It significantly reduces quality of life due to itching, sleep disturbance, and social stigma. Healthcare costs are substantial, with frequent clinic visits and treatments.
- Pathophysiology overview: Eczema involves a defective skin barrier due to filaggrin gene mutations and an overactive type 2 immune response. This leads to increased transepidermal water loss and susceptibility to irritants and microbes. Understanding the pathophysiology guides the use of barrier repair therapies and targeted biologics.
- Common triggers: Environmental factors such as dry air, wool clothing, dust mites, pet dander, and certain foods can provoke flares. Stress and hormonal changes also play a role. Patients are encouraged to maintain a symptom diary to identify personal triggers and develop avoidance strategies.
- Infection risk: Eczema patients have a higher risk of skin infections, particularly Staphylococcus aureus and viral infections like eczema herpeticum. Signs include increased redness, weeping, crusting, and pain. Prompt treatment with antibiotics or antivirals is necessary to prevent complications.
Terminology
- Eczema
- A general term for inflammatory skin conditions causing redness, itching, and scaling.
- Atopic dermatitis
- The most common type of eczema, associated with a genetic tendency to develop allergic conditions.
- Contact dermatitis
- Inflammation resulting from skin contact with an irritant or allergen.
- Seborrheic dermatitis
- A chronic form of eczema affecting sebaceous areas, linked to yeast overgrowth.
- Dyshidrotic eczema
- A vesicular eczema of the hands and feet, often triggered by stress or metals.
Quick Revision
- Eczema is a group of inflammatory skin conditions with atopic dermatitis being the most common.
- Contact dermatitis can be irritant or allergic, with distinct causes.
- Seborrheic, dyshidrotic, nummular, and stasis dermatitis are less common variants.
- Understanding subtypes guides targeted management and patient education.