What is the treatment for skin fungal infections?

Treatment for Skin Fungal Infections

Topical antifungal agents are the first-line treatment for most skin fungal infections, with specific systemic therapy reserved for extensive, resistant, or specific types of infections. 1

Treatment by Type of Skin Fungal Infection

Candidal Skin Infections and Intertrigo

• Topical azoles (clotrimazole, miconazole) and polyenes (nystatin) are effective for treating candidal skin infections, especially in skin folds of obese and diabetic patients 1
• Keeping the infected area dry is crucial for successful treatment 1
• For paronychia (infection around the nail), drainage is the most important intervention, followed by antifungal therapy 1

Dermatophyte Infections (Tinea)

Tinea Corporis/Cruris (Body/Groin)

• Topical azoles or allylamines for 2-4 weeks are typically effective 2, 3
• For widespread or resistant infections, oral therapy may be required:
  • Fluconazole 150 mg once weekly for 2-3 weeks 4
  • Itraconazole 100 mg daily for 2 weeks or 200 mg daily for 7 days 4
  • Terbinafine 250 mg daily for 1-2 weeks 4

Tinea Pedis (Athlete's Foot)

• Topical antifungals for 4-8 weeks 2, 3
• For extensive or resistant cases, oral therapy:
  • Fluconazole 150 mg once weekly 4
  • Itraconazole 100 mg daily for 2 weeks or 400 mg daily for 1 week 4
  • Terbinafine 250 mg daily for 2 weeks 4

Tinea Unguium (Onychomycosis)

• Topical agents are usually ineffective for nail infections 1, 3
• Oral therapy is required:
  • For fingernails: at least 4 months of treatment 2
  • For toenails: at least 6 months of treatment 2
  • Terbinafine or itraconazole are preferred over griseofulvin for most cases 1
  • For Candida onychomycosis specifically, azoles are preferred as terbinafine has limited activity 1

Tinea Capitis (Scalp)

• Requires oral antifungal therapy 2, 5
• Griseofulvin 10 mg/kg daily for 4-6 weeks is effective 2
• For children: dosage based on weight (30-50 lbs: 125-250 mg daily; over 50 lbs: 250-500 mg daily) 2

General Principles for Treatment

• Accurate diagnosis is essential before starting treatment - direct microscopic examination with potassium hydroxide (KOH) or culture should be performed 2, 5
• Treatment must continue until the infecting organism is completely eradicated 2
• Concomitant use of appropriate topical agents is often required, particularly for tinea pedis 2
• General hygiene measures should be observed to control sources of infection or reinfection 2

Choosing Between Topical Agents

• Azoles (miconazole, clotrimazole, ketoconazole): Fungistatic agents that are particularly effective for yeast infections like Candida 3
• Allylamines and benzylamines (terbinafine, naftifine, butenafine): Fungicidal agents that are preferred for dermatophyte infections due to shorter treatment times and higher cure rates 3
• For weeping infections, spray formulations may be preferred by patients 3

When to Use Systemic Therapy

Oral antifungal therapy should be considered when:

• The infection is widespread or involves an extensive area 6, 5
• The infection is resistant to topical therapy 2, 6
• The infection involves hair follicles or nails 3, 5
• For specific infections like tinea capitis that require systemic treatment 2, 5

Common Pitfalls and Caveats

• Premature discontinuation of therapy when symptoms improve but before complete eradication of the fungus 3
• Failure to identify and treat bacterial co-infections, especially in tinea pedis 2
• Not keeping the infected area dry, particularly for intertrigo 1
• Using topical therapy alone for nail infections or tinea capitis, which typically require systemic treatment 1, 3
• Not considering non-dermatophyte causes of skin infections that may not respond to standard antifungal therapy 2