What is the treatment for nummular eczema flare-ups?

Treatment of Nummular Eczema Flare-Ups

Apply high-potency or ultra-high potency topical corticosteroids 2-3 times daily to the coin-shaped lesions as first-line treatment for nummular eczema flare-ups, combined with aggressive emollient therapy. 1, 2

First-Line Topical Corticosteroid Strategy

• Use high-potency or ultra-high potency topical corticosteroids as the mainstay of therapy for active nummular eczema lesions, applying them 2-3 times daily depending on severity 1, 2
• Potent topical corticosteroids result in a large increase in treatment success (70% versus 39% with mild-potency) for moderate to severe eczema 3
• Once-daily application of potent topical corticosteroids is probably as effective as twice-daily application, though the FDA label supports 2-3 times daily for severe conditions 3, 2
• Continue treatment until lesions clear, which typically takes a few weeks with proper therapy 1

Essential Emollient Therapy

• Liberal and frequent application of emollients is mandatory and should be continued even after lesions appear controlled 4, 1
• Apply emollients immediately after bathing to provide a surface lipid film that retards water loss 4
• Use soap-free cleansers and avoid hot water baths, as these remove natural skin lipids and are common aggravating factors 5, 6
• Moisturizing the skin and avoiding harsh soaps may reduce the frequency of recurrence 1

Managing Pruritus

• Prescribe sedating antihistamines (diphenhydramine, clemastine) exclusively at nighttime to help patients sleep through severe itching episodes 4, 5
• Large doses may be required in children to achieve adequate symptom control 7
• Non-sedating antihistamines have little to no value in eczema and should not be used 4, 5
• Sedating antihistamines work through their sedative properties, not through direct anti-pruritic effects 4

Identifying and Treating Secondary Infection

• Watch for increased crusting, weeping, or pustules—these indicate secondary bacterial infection requiring oral antibiotics 4, 5
• Flucloxacillin is the first-line oral antibiotic for Staphylococcus aureus, the most common pathogen 4, 5
• Continue topical corticosteroids during bacterial infection when appropriate systemic antibiotics are given concurrently 4
• If you observe grouped vesicles, punched-out erosions, or sudden deterioration with fever, suspect eczema herpeticum—this is a medical emergency 4
• Initiate oral acyclovir early; in ill, feverish patients, administer acyclovir intravenously 4

Identifying Aggravating Factors

• Emotional stress and alcohol consumption are common aggravating factors that should be addressed 6
• Contact allergy is common with nummular eczema—consider patch testing in patients with chronic, recalcitrant disease 1
• Nickel is the most common allergen identified on patch testing 6
• Patients with exacerbation in summer or persistent skin dryness tend to have more persisting disease 6

Preventing Relapse After Clearing

• After achieving clearance, implement proactive (weekend) therapy with topical corticosteroids applied twice weekly to previously affected sites 7
• Weekend proactive therapy results in a large decrease in likelihood of relapse from 58% to 25% compared to reactive use only 3
• This proactive approach is supported by five randomized controlled trials showing reduced risk of flare development over 16-20 weeks 7
• Continue aggressive emollient use daily, even when skin appears clear 4, 1

Common Pitfalls to Avoid

• Do not use mild-potency corticosteroids for nummular eczema flare-ups—they are inadequate for this condition 1, 3
• Do not delay or withhold topical corticosteroids when infection is present—they remain the primary treatment when appropriate systemic antibiotics are given 4
• Avoid very potent corticosteroids on thin-skinned areas (face, neck, flexures), though nummular eczema typically affects the extremities 4, 6
• Do not use continuous topical corticosteroids without breaks—implement "steroid holidays" when possible to minimize side effects 7, 4

When to Escalate or Refer

• Failure to respond to high-potency topical corticosteroids after 4 weeks warrants referral 4
• Chronic, recalcitrant cases may require patch testing to identify contact allergens 1
• Systemic corticosteroids have a limited role only for severe cases after exhausting all other options, and should never be used for maintenance 7, 4
• The course is typically chronic with relapses and remissions, but proper treatment can clear lesions over a few weeks 1, 6