Discoid Eczema (Nummular Dermatitis) – Diagnosis & Treatment in London

What is discoid eczema?

Discoid eczema, also known as nummular eczema, is a distinct type of eczema that produces coin-shaped patches of inflamed skin. These lesions may start as small red bumps before merging into larger circular plaques. The condition is often intensely itchy and may ooze fluid during flares before eventually crusting and healing with post-inflammatory pigmentation. The pattern is chronic and relapsing, with periods of improvement followed by recurrence.

Causes and triggers

The exact cause of discoid eczema remains unclear, but it is linked to a combination of genetic, immune, and environmental factors. Triggers often include dry skin, exposure to irritants such as soaps and detergents, temperature changes, skin injury, and underlying atopic tendencies. Stress, alcohol use, and infections may also precipitate flare-ups.

Who gets discoid eczema?

This condition can affect anyone, but men over 50 are disproportionately affected, as are women in early adulthood. People with a personal or family history of atopic eczema, asthma, or hay fever are also at higher risk. It can affect all skin types and tones, though the appearance of redness or pigmentation changes may vary.

Symptoms and diagnosis

The hallmark of discoid eczema is round or oval lesions, usually on the arms, legs, or torso. These patches may be red, itchy, scaly, and occasionally oozing. In darker skin tones, they may appear more purple or brown. Over time, healed lesions often leave behind darker or lighter areas of pigmentation. Diagnosis is clinical, though skin scrapings or biopsies may be performed to rule out fungal infection or psoriasis.

Management and treatment options

Treatment focuses on relieving symptoms, reducing inflammation, and preventing recurrence. Options include:

• Emollients: Regular moisturisation to restore the skin barrier.
• Topical corticosteroids: Applied to inflamed patches to reduce redness and itching.
• Antibiotics: For secondary bacterial infections.
• Phototherapy: Controlled light therapy for widespread or resistant disease.
• Systemic treatments: In severe or refractory cases, oral corticosteroids or immunosuppressants may be considered.

Lifestyle and prevention

Preventing flare-ups involves good skin care habits and avoiding known triggers. Patients are advised to:

• Moisturise daily, especially after bathing.
• Use fragrance-free, gentle cleansers and avoid harsh soaps.
• Wear protective gloves when exposed to water or chemicals.
• Avoid scratching to reduce infection risk.
• Limit alcohol intake and manage stress levels.

Discoid eczema in skin of colour

In skin of colour, discoid eczema may present with dark brown or greyish lesions rather than the classic red patches. Post-inflammatory pigmentation changes can be more pronounced, making cosmetic impact significant even after active inflammation subsides. Special consideration is required in treatment to address both active disease and pigmentation outcomes.

Why choose Skinhorizon?

At Skinhorizon, we combine dermatological expertise with advanced treatment options to manage discoid eczema effectively. Our team provides tailored care, from prescription therapies to in-clinic phototherapy, while supporting lifestyle changes that reduce relapses. We take a patient-centred approach, considering both skin health and overall wellbeing.

Your first visit — what to expect

1. Consultation: Comprehensive assessment of your skin and history.
2. Diagnosis: Confirmation of discoid eczema and exclusion of similar conditions.
3. Treatment plan: Discussion of topical, systemic, and supportive options.
4. Practical advice: Guidance on skincare and lifestyle adaptations.
5. Follow-up: Ongoing support to adjust therapy and monitor progress.

Reviewed by: Dr Mohammad Ghazavi, Consultant Dermatologist
Skinhorizon Clinic, 4 Clarendon Terrace, Maida Vale, London W9 1BZ
Last reviewed: 20 August 2025