Eczema — Symptoms, Causes & Treatment | MyMedicPlus

Eczema, most commonly atopic dermatitis, is a chronic inflammatory skin condition characterized by intensely itchy, inflamed, and dry skin. It affects 10–20% of children and 1–3% of adults, with over 230 million people affected globally. Eczema often begins in early childhood and may persist into adulthood. It is part of the atopic triad alongside asthma and allergic rhinitis, and frequently occurs in individuals with a family history of allergic conditions. The condition follows a relapsing-remitting course, with flares triggered by environmental factors, infections, or emotional stress, interspersed with periods of relative remission. Eczema significantly impairs quality of life through nocturnal sleep disruption, social embarrassment, and the time burden of daily skincare routines. The underlying immunological mechanism is predominantly type 2 inflammation driven by IL-4, IL-13, and IL-31 cytokines — with IL-31 being a major mediator of the intense itch response characteristic of this condition.

Eczema results from an interaction between genetic susceptibility, skin barrier dysfunction, and immune dysregulation. Mutations in the filaggrin gene (FLG) impair the skin barrier, allowing allergens and irritants to penetrate and trigger immune activation with a Th2-skewed response. Key risk factors include family history of atopic conditions, early antibiotic exposure, urban environment, low microbial diversity in infancy, and food allergies. Triggers include soaps, detergents, wool, sweat, stress, and temperature extremes. Staphylococcus aureus colonizes the skin of 90% of patients with atopic dermatitis and directly perpetuates immune activation by releasing proteases that damage the skin barrier and superantigens that stimulate T-cell proliferation. Reduced microbial diversity in the early-life skin and gut microbiome is increasingly recognized as a contributing factor to atopic disease development.

Intense pruritus (itch) is the hallmark symptom and is often worse at night, disrupting sleep significantly. Affected skin appears dry, red, and inflamed with vesicles, crusting, and excoriation marks from scratching. In infants, eczema typically affects the cheeks, scalp, and extensor surfaces. In older children and adults, flexural areas (antecubital fossae, popliteal fossae, neck, wrists) are most commonly involved. Chronic disease leads to skin thickening (lichenification) and post-inflammatory hyperpigmentation from repeated inflammation cycles. Disease severity is assessed using validated tools such as the EASI (Eczema Area and Severity Index) and SCORAD, which quantify extent and intensity of skin involvement and guide decisions on treatment escalation from topical to systemic therapy.

Eczema is diagnosed clinically based on history and physical examination. The UK Working Party diagnostic criteria require pruritic skin disease plus at least three of: visible flexural dermatitis, history of atopic conditions, generally dry skin, and onset under age 2. Patch testing identifies contact allergens in cases of suspected contact dermatitis overlap. Skin prick testing or specific IgE measurement identifies food and aeroallergen sensitivities in selected patients with suspected allergic triggers driving their eczema flares. Total serum IgE is frequently elevated but is not required for diagnosis. Skin biopsy, showing non-specific spongiotic dermatitis, is occasionally performed when an unusual presentation raises concern for mycosis fungoides (cutaneous T-cell lymphoma) or other diagnoses that can clinically mimic eczema in adult patients.

Regular use of emollients (moisturizers) is the foundation of eczema management, repairing the skin barrier and reducing flare frequency. Mild-to-moderate flares are treated with topical corticosteroids (hydrocortisone 1% for face; stronger preparations for body). Topical calcineurin inhibitors (tacrolimus, pimecrolimus) are steroid-sparing options for sensitive areas. Dupilumab (IL-4/IL-13 biologic inhibitor) has transformed moderate-to-severe eczema treatment, achieving clear or almost-clear skin in over 60% of patients. JAK inhibitors (abrocitinib, upadacitinib) provide additional oral treatment options for refractory cases. For infected eczema, oral flucloxacillin or a topical antibiotic (fusidic acid) treats Staphylococcal superinfection; widespread eczema herpeticum requires urgent systemic aciclovir. Wet wrapping — applying diluted topical corticosteroids under wet bandages overnight — provides rapid symptomatic relief during severe flares by enhancing drug penetration and creating a physical barrier against scratching.

Chronic sleep disruption from nocturnal pruritus significantly impairs quality of life, cognitive function, and mood, often leading to clinical depression and anxiety. Bacterial superinfection with Staphylococcus aureus (which colonizes 90% of eczema skin) causes weeping, crusted, and worsening flares. Eczema herpeticum — widespread herpes simplex infection across broken skin — is a medical emergency requiring urgent antiviral treatment. Long-standing eczema significantly increases subsequent risk of asthma and food allergy as part of the atopic march. Eczema also markedly increases the likelihood of contact sensitization to multiple allergens, since the disrupted skin barrier allows easier penetration by potential sensitizers, leading to overlapping allergic contact dermatitis that complicates management.

Apply emollients liberally to all skin immediately after bathing to lock in moisture while skin is still damp. Avoid known triggers including harsh soaps, fragrances, wool, excessive heat, and specific allergens. Use fragrance-free, gentle laundry detergents on all clothing and bedding. Maintain a cool, humid sleep environment. Evidence suggests early daily emollient use from birth may reduce the risk of eczema development in high-risk infants. Probiotic supplementation in pregnancy and infancy shows modest preventive benefit in reducing atopic disease risk.

Seek emergency care immediately for: fever with widespread blistered, painful eczema spreading rapidly (possible eczema herpeticum — herpes simplex virus infection on broken skin — requires urgent oral or IV aciclovir); signs of spreading skin infection (cellulitis — increasing redness, warmth, swelling, fever). See your GP within 24–48 hours for: weeping, golden-crusted eczema (likely infected with Staphylococcus aureus — requires topical or oral antibiotics plus topical steroid); eczema significantly interfering with sleep or daily activities. Refer to a dermatologist if: eczema is not responding to prescription-strength topical corticosteroids and is causing significant quality-of-life impairment — dupilumab (biologic) or JAK inhibitors are highly effective for moderate-to-severe disease but require specialist prescription. Allergy testing (food and environmental) should be considered for children under 5 with moderate-to-severe eczema not responding to standard treatment — food allergens can drive eczema in this age group.