What is the best treatment for an eczema rash on a patient's buttocks?

Treatment of Eczema Rash on the Buttocks

For eczema on the buttocks, apply a moderate potency topical corticosteroid such as clobetasone butyrate 0.05% cream twice daily for 1-2 weeks, followed by regular emollient application. 1

First-Line Treatment Approach

Topical Corticosteroids

• Start with a moderate potency topical corticosteroid:
  • Clobetasone butyrate 0.05% (Eumovate) 2, 1
  • Apply as a thin layer twice daily for 1-2 weeks 1, 3
  • Use cream formulation if the skin is weeping; ointment if the skin is dry 2
  • For the buttocks area, approximately 100g of cream/ointment would be needed for a 2-week treatment course 2

Emollients

• Apply emollients liberally and frequently throughout the day 1
• Suitable options include:
  • Diprobase cream/ointment
  • Cetraben
  • Epaderm cream
  • Hydromol cream/ointment 2
• Apply at least 15-30 minutes before or after corticosteroid application 1

Management of Infection

If signs of infection are present (increased redness, weeping, crusting):

• Add topical antibiotics in alcohol-free formulation for at least 14 days 2, 1
• Consider oral antibiotics if infection is widespread:
  • Flucloxacillin is usually most appropriate for Staphylococcus aureus
  • Erythromycin if penicillin allergy is present 2, 1

Treatment Escalation

If no improvement after 2 weeks of appropriate treatment:

• Consider increasing to a potent corticosteroid such as betamethasone valerate 0.1% for a short duration (3-7 days) 1, 4
• Research shows that a short burst (3 days) of potent corticosteroid can be as effective as prolonged use of a mild preparation 4
• Return to moderate potency once improvement is seen 1

Maintenance Therapy

For recurrent eczema on the buttocks:

• Consider proactive, intermittent application (twice weekly) of moderate potency corticosteroid to prevent flares 1, 5
• Weekend therapy (proactive approach) significantly reduces the likelihood of relapse compared to reactive treatment (25% vs 58% relapse rate) 5

Important Considerations and Precautions

Corticosteroid Potency

• Avoid very potent corticosteroids on the buttocks unless specifically directed by a dermatologist 1
• Risk of skin thinning increases with higher potency corticosteroids 5, 6
• Evidence suggests that when used appropriately, the risk of skin thinning with moderate potency corticosteroids is low (reported in only 1% of patients across multiple studies) 5, 7

Adjunctive Treatments

• Sedating antihistamines can be used short-term for severe itching, particularly at night 2, 1
• Non-sedating antihistamines have little value for eczema-related itch 2
• Ichthammol 1% in zinc ointment or paste bandages may be helpful for lichenified (thickened) areas 2

When to Refer

• If no improvement after 2 weeks of appropriate treatment 1
• If infection is not responding to antibiotics 1
• If eczema is severe or recalcitrant despite appropriate treatment 2

Patient Education

• Reassure patients about corticosteroid safety when used appropriately - studies show that patient fears about topical corticosteroids often lead to undertreatment 6
• Long-term studies (up to 5 years) show reassuring data on growth and skin thinning when topical corticosteroids are used intermittently 7
• Emphasize the importance of regular emollient use even when the eczema has cleared 1

By following this treatment approach, most patients with eczema on the buttocks should experience significant improvement in symptoms and quality of life.