What's the next step for a 18-65 year old patient with a stable medical history, no significant liver or kidney disease, who has a persistent forehead rash unresponsive to miconazole, triamcinolone, and clobetasol, and has recently completed antifungal treatment with Terbinafine (terbinafine) for a resolved toenail fungal infection?

Refractory Forehead Rash After Failed Topical Therapy

The next step is to obtain a skin scraping with KOH preparation and fungal culture to identify the specific organism and perform susceptibility testing, as this persistent rash unresponsive to multiple topical antifungals and corticosteroids likely represents azole-resistant Candida or a non-Candida etiology. 1

Diagnostic Workup

The failure to respond to miconazole (antifungal), triamcinolone (mid-potency steroid), and clobetasol (high-potency steroid) suggests either:

• Azole-resistant Candida species (particularly C. glabrata or C. krusei) 2
• Non-Candida fungal infection that requires different therapy 2
• Non-fungal dermatologic condition misdiagnosed as fungal

Key Diagnostic Steps:

• Perform skin scraping with KOH preparation to visualize fungal elements immediately 1
• Send fungal culture to identify the specific organism and perform susceptibility testing if Candida is isolated 1
• This is critical because terbinafine has limited and unpredictable activity against Candida species, despite being highly effective for dermatophytes 2, 3

Treatment Options for Confirmed Azole-Resistant Cutaneous Candidiasis

If culture confirms azole-resistant Candida (particularly C. glabrata):

First-Line Options:

• Compounded topical flucytosine 17% cream alone or combined with amphotericin B 3% cream for 14 days 1
• Oral fluconazole at higher doses (400 mg daily) for refractory cutaneous candidiasis 1

Alternative Considerations:

• Topical boric acid 600 mg daily for 14 days may be considered, though primarily studied for vulvovaginal candidiasis 1
• Echinocandins (caspofungin, micafungin, anidulafungin) lack robust data for cutaneous disease but may be used for confirmed refractory cases 1

Important Clinical Caveats

Why Terbinafine Likely Didn't Help:

• Terbinafine is highly potent against dermatophytes but has limited and unpredictable activity against Candida species 2, 3
• While one study showed 60% cure rates for Candida nail infections with 16 weeks of terbinafine, this is significantly lower than its efficacy for dermatophytes 3
• The patient's recent terbinafine exposure may have selected for azole-resistant Candida if the forehead rash was fungal 2

Differential Diagnosis to Consider:

If fungal studies are negative, consider:

• Seborrheic dermatitis (common on forehead, can mimic fungal infection)
• Contact dermatitis (may not respond to antifungals/steroids if allergen exposure continues)
• Psoriasis (can be steroid-resistant)
• Rosacea (can worsen with topical steroids)

Monitoring During Treatment:

• If prolonged oral azole therapy is required (>21 days), monitor liver function tests periodically 2
• Response to appropriate antifungal therapy should occur within 48-72 hours for true Candida infections 2