What are the next steps for an adult patient with no significant medical history, who presented with erythematous rashes in multiple skin folds suggestive of candidal intertrigo, and showed improvement with mupirocin (mupirocin) plus betamethasone (betamethasone)?

Management After Resolution with Mupirocin Plus Betamethasone

Stop the combination therapy immediately and transition to appropriate antifungal treatment, as the clinical improvement with mupirocin-betamethasone strongly suggests this was NOT candidal intertrigo but rather a bacterial infection (likely staphylococcal or streptococcal) with secondary inflammation. 1

Why the Diagnosis Needs Reconsideration

The response to mupirocin (antibacterial) plus betamethasone (corticosteroid) indicates this was likely:

• Bacterial intertrigo (Staphylococcus aureus or Streptococcus) rather than candidal infection 1
• Secondarily infected dermatitis that responded to the antibacterial component 2
• The betamethasone reduced inflammation while mupirocin eradicated the bacterial pathogen 2

True candidal intertrigo would NOT improve with mupirocin-betamethasone alone - it requires antifungal therapy with agents like nystatin, clotrimazole, or ketoconazole 1. In fact, corticosteroids alone can worsen fungal infections.

Immediate Next Steps

1. Discontinue Current Therapy

• Stop mupirocin after 5-10 days maximum to prevent resistance development 3, 4
• Taper or stop betamethasone once inflammation is controlled to avoid steroid-related adverse effects 5
• Prolonged topical corticosteroid use in intertriginous areas carries high risk of skin atrophy 6

2. Address Predisposing Factors

• Treat underlying moisture and friction in skin folds 6
• Examine interdigital toe spaces for fissuring, scaling, or maceration that may harbor bacterial colonization 6
• Implement measures to keep affected areas dry and reduce friction 1

3. Monitor for Recurrence

• If lesions recur after stopping therapy, this suggests:
  • Persistent bacterial colonization requiring decolonization protocols 3
  • Unaddressed predisposing factors (obesity, diabetes, poor hygiene) 1

If Bacterial Infection Confirmed

For Prevention of Recurrence:

• Intranasal mupirocin decolonization: Apply twice daily for the first 5 days each month (reduces recurrences by ~50%) 3
• Daily chlorhexidine body washes combined with intranasal mupirocin for comprehensive decolonization 3
• Daily decontamination of personal items like towels and sheets 3

Duration Considerations:

• Standard mupirocin treatment is 5-10 days 3, 4
• Patients not showing clinical response within 3-5 days should be re-evaluated 4

Critical Pitfalls to Avoid

Do not continue combination therapy long-term - the 2023 American Academy of Dermatology guidelines explicitly state that combining mupirocin with topical corticosteroids (hydrocortisone butyrate, clobetasol, or betamethasone) provides NO additional benefit over corticosteroid alone for dermatologic conditions 6

Do not assume this was candidal intertrigo - the therapeutic response pattern contradicts that diagnosis 1

Do not use betamethasone as maintenance therapy in skin folds - if ongoing anti-inflammatory therapy is needed, consider medium-potency topical corticosteroids twice weekly rather than continuous high-potency agents 6

When to Escalate Care

Consider systemic antibiotics if:

• Extensive surrounding cellulitis or fever develops 6, 3
• Infection recurs within days of stopping therapy 3
• Signs of deeper soft tissue involvement appear 6
• Patient is immunocompromised with significant infection 6