Treatment of Nummular Eczema

First-Line Treatment

The British Medical Journal recommends topical corticosteroids as the mainstay of treatment for nummular eczema, with the least potent preparation required to control symptoms being recommended, along with proper skin hydration and avoidance of irritants 1, 2
Patients with nummular eczema should avoid soaps and detergents that remove natural skin lipids and use dispersible cream as a soap substitute 2
Avoidance of extreme temperatures and irritant clothing, such as wool, is recommended, with cotton clothing being preferred 1, 2
Keeping nails short is advised to minimize damage from scratching 2
Regular bathing is beneficial for both cleansing and hydrating the skin, and emollients should be applied after bathing to provide a surface lipid film that retards evaporative water loss 1
Patients should be allowed to determine the most suitable bath oil and bathing regimen for their condition 1
The use of the least potent preparation required to keep the eczema under control is recommended, and corticosteroids should be stopped for short periods to minimize side effects when possible 1
Treatment should not be applied more than twice daily 1

Ichthammol (1% in zinc ointment) is less irritant than coal tars and particularly useful for lichenified eczema, while coal tar solution (1% in hydrocortisone ointment) is generally preferred to crude coal tar 1
These preparations do not cause systemic side effects unless used extravagantly 1
Antihistamines are primarily valuable for their sedative properties during severe pruritic episodes and are useful as short-term adjuvants to topical treatment during relapses with severe itching 1
Non-sedating antihistamines have little to no value in treating nummular eczema, and antihistamines should be used primarily at night while asleep, with daytime use being avoided 1
Antibiotics are important for treating overt secondary bacterial infection, with flucloxacillin being usually most appropriate for Staphylococcus aureus, and phenoxymethylpenicillin for β-hemolytic streptococci, and erythromycin for penicillin allergy 1
Herpes simplex infection (eczema herpeticum) requires oral acyclovir early in the disease course 1

In children, topical corticosteroids should be used cautiously due to the risk of pituitary-adrenal axis suppression 1
Systemic corticosteroids have a limited role and should only be considered after all other treatments have been explored 3
Most patients respond well to first-line management and don't require specialist referral, but consideration for referral should be given to patients with treatment failure, extensive disease, or diagnostic uncertainty 3