What is the treatment for nummular eczema?

Treatment of Nummular Eczema

The treatment of nummular eczema should primarily consist of topical corticosteroids as the mainstay therapy, with the least potent preparation required to control symptoms, along with proper skin hydration and avoidance of irritants. 1

First-Line Treatment

Topical Therapy

• Apply topical corticosteroids of appropriate potency to control inflammation - use the least potent preparation that effectively manages symptoms 1
• Treatment should not be applied more than twice daily, with some newer preparations requiring only once-daily application 1
• Regular use of emollients after bathing to provide a surface lipid film that retards evaporative water loss 1
• Use dispersible cream as a soap substitute instead of regular soaps and detergents that remove natural skin lipids 1

Skin Care and Prevention

• Regular bathing is beneficial for both cleansing and hydrating the skin 1
• Avoid extreme temperatures and irritant clothing (such as wool); cotton clothing is preferred 1
• Keep nails short to minimize damage from scratching and reduce risk of secondary infection 1
• Allow patients to determine the most suitable bath oil and bathing regimen for their condition 1

Management of Secondary Infections

• Antibiotics are important for treating overt secondary bacterial infections 2, 1
• Flucloxacillin is usually the most appropriate antibiotic for treating Staphylococcus aureus (the commonest pathogen) 2, 1
• Phenoxymethylpenicillin should be given if β-hemolytic streptococci are isolated 2
• Erythromycin may be used when there is resistance to flucloxacillin or in patients with penicillin allergy 2
• For herpes simplex infection (eczema herpeticum), oral acyclovir should be given early in the disease course; in ill, feverish patients, acyclovir should be administered intravenously 2

Second-Line Treatment Options

• Ichthammol (1% in zinc ointment) is less irritant than coal tars and particularly useful for lichenified eczema 1
• Coal tar solution (1% in hydrocortisone ointment) is generally preferred to crude coal tar and does not cause systemic side effects unless used extravagantly 2, 1
• Sedating antihistamines can be useful as a short-term adjuvant to topical treatment during relapses with severe pruritus, primarily for their sedative properties 2, 1
• Non-sedating antihistamines have little to no value in treating nummular eczema 2, 1
• Antihistamines should be used primarily at night while asleep, with daytime use being avoided 1

Third-Line Treatment Options

• Consider phototherapy for moderate to severe eczema not responding to first-line treatments 3
• Systemic corticosteroids have a limited but definite role in tiding occasional patients with severe nummular eczema 2, 1
• The decision to use systemic steroids should never be taken lightly and they should not be considered for maintenance treatment until all other avenues have been explored 2
• Methotrexate may be considered for severe cases in children that fail to respond to conventional topical therapy, with studies showing complete or marked improvement in over 80% of pediatric patients 4

Special Considerations

• Investigate for potential dental infections in treatment-resistant cases, as latent odontogenic infection may be an aggravating factor 5
• Consider patch testing in patients with chronic, recalcitrant nummular eczema, as contact allergy is common 6
• Be aware that emotional stress and alcohol consumption can aggravate the disease 7
• In children, topical corticosteroids should be used cautiously due to the risk of pituitary-adrenal axis suppression 1, 8

When to Refer to a Specialist

• Consider referral if there is failure to respond to first-line treatment, extensive disease, or diagnostic uncertainty 3, 1
• Specialists should start with first-line treatment measures again, reinforcing any aspects in which there was lack of compliance 3

Common Pitfalls and Caveats

• Avoid using very potent and potent topical corticosteroid categories for extended periods, especially on the face 2, 3
• Be aware that nummular eczema often has a chronic and relapsing course, requiring long-term management strategies 6, 7
• Don't overlook the significant impact on quality of life, particularly due to itching 7
• Remember that nummular eczema may mimic other annular lesions, requiring careful differential diagnosis 6
• Consider that patients with exacerbation in summer or skin dryness tend to have more persistent disease 7