Fungal Skin Infections

Epidemiology and Clinical Presentation

Fungal skin infections present as superficial mucosal and cutaneous infections in up to 80% of high-risk patients, typically appearing as single or multiple nodular skin lesions, discrete pink to red papules (0.5-1.0 cm) on the trunk and extremities 1, 2
They can manifest as intertrigo, vaginitis, balanitis, perleche, and paronychia, and may become painful and hemorrhagic in thrombocytopenic patients 2
Cutaneous infections are unusual but may occur at IV catheter insertion sites or nail beds, with Rhizopus and Mucor species causing erythematous, nodular, and tender skin lesions 1
Fusarium infections present as multiple erythematous macules with central pallor that quickly evolve to papules and necrotic nodules, while Trichosporon beigelii causes multiple erythematous macules to maculopapular lesions 1, 2
Immunocompromised patients are at higher risk for invasive fungal infections with cutaneous manifestations, including onychomycosis, which can serve as a reservoir for subsequent disseminated infection 3, 4

Wet mount preparation with saline and 10% potassium hydroxide can demonstrate yeast or hyphae, while tissue biopsy with histopathological examination using fungal stains (Grocott methenamine silver) is used for invasive infections 5, 6
Serum fungal antigen tests (1,3-β-D-glucan or galactomannan) may have low sensitivity, particularly in patients receiving antifungal agents 2
Direct microscopy with potassium hydroxide preparation, fungal culture of skin scrapings or biopsy material, and Wood's lamp examination can also be used to diagnose fungal infections 5
Skin biopsy with histopathological examination can be used to diagnose invasive fungal infections 6

Fungal skin infections can be effectively treated with improved skin care and topical antifungal agent or short-course systemic azole (e.g., fluconazole), with treatment options based on organism including:
For vaginal candidiasis, the American College of Obstetricians and Gynecologists recommends a single 150-mg dose of fluconazole for uncomplicated cases, while complicated cases can be treated with topical therapy or multiple doses of fluconazole 5
Recurrent cases of vaginal candidiasis can be treated with 10-14 days of induction therapy with topical or oral azole, followed by fluconazole 150 mg once weekly for 6 months 5
For C. glabrata infections, topical boric acid (600 mg daily for 14 days) may be successful when azoles fail 5

Good personal hygiene is an important adjunct to antifungal therapy, although the strength of evidence for this is not provided 5
For recurrent infections, maintenance therapy may be required, with a moderate strength of evidence supporting this approach 5
Fluconazole-resistant yeast (C. krusei and C. glabrata) are increasingly common due to widespread use of azole prophylaxis, with a high strength of evidence supporting this statement 2
Invasive fungal infections with cutaneous manifestations require aggressive systemic therapy and sometimes surgical debridement, with the American College of Radiology recommending immediate evaluation and aggressive treatment for fungal skin infections in immunocompromised children 7, 8