What are the prescription treatments for scalp fungal irritation?

Prescription Treatments for Scalp Fungal Irritation

For scalp fungal infections (tinea capitis), oral antifungal medications are the primary treatment as topical therapy alone is ineffective. The choice of medication depends on the causative organism, with different treatments recommended for Trichophyton versus Microsporum species.

First-Line Oral Treatments

• Griseofulvin remains the only FDA-approved medication for tinea capitis in children in the UK, typically dosed at 15-20 mg/kg/day for 6-8 weeks (or 1g daily for those >50kg) 1
• Terbinafine is highly effective against Trichophyton species infections with dosing based on weight:
  • <20 kg: 62.5 mg daily for 2-4 weeks
  • 20-40 kg: 125 mg daily for 2-4 weeks

  • 40 kg: 250 mg daily for 2-4 weeks 1

• Itraconazole is effective against both Trichophyton and Microsporum species, though it's not FDA-approved specifically for tinea capitis 2
• Fluconazole can be used as an alternative, particularly in younger children as it's available in liquid form 3

Treatment Selection Based on Causative Organism

• For Trichophyton species infections:

  • Terbinafine is more effective than griseofulvin for T. tonsurans infections (52.1% vs 35.4% cure rate) 4
  • Terbinafine for 4 weeks shows similar efficacy to griseofulvin for 8 weeks (84.2% vs 79.0% cure rate) 4

• For Microsporum species infections:

  • Griseofulvin is more effective than terbinafine (50.9% vs 34.7% cure rate) 4
  • Itraconazole may be more effective than terbinafine for M. canis infections 2

Adjunctive Topical Treatments

• Antifungal shampoos containing selenium sulfide 1% can help reduce spore shedding and prevent spread 3
• Ketoconazole 2% shampoo can be used as an adjunctive treatment 1
• Topical corticosteroids may help relieve inflammation, itching, and other symptoms associated with fungal scalp infections 1

Second-Line Treatments

• Itraconazole can be used when first-line treatments fail, though caution is needed due to potential cardiac effects and drug interactions 5
• Fluconazole (100-200 mg daily for 7-14 days) can be effective for moderate to severe fungal infections 6
• Sulfamethoxazole-trimethoprim has been cited as effective against head lice and some fungal infections, though it's not FDA-approved for this purpose 1

Special Considerations

• Duration of treatment is typically:

  • 6-8 weeks for griseofulvin
  • 2-4 weeks for terbinafine, itraconazole, or fluconazole 1, 4

• Monitoring:

  • Liver enzyme monitoring is generally unnecessary if therapy is limited to ≤4 weeks 3
  • Most adverse events with these medications are mild and reversible, with gastrointestinal symptoms being most common 4

• Treatment failure may be due to:

  • Incorrect diagnosis
  • Noncompliance with treatment protocol
  • Reinfestation
  • Resistance to the antifungal agent 1

Cautions and Contraindications

• Itraconazole has been associated with rare cases of serious hepatotoxicity and cardiac dysrhythmias 5
• Lindane (1%) shampoo should only be used as a second-line treatment due to potential neurotoxicity and is contraindicated in neonates and individuals weighing less than 50 kg 1
• Griseofulvin is contraindicated in lupus erythematosus, porphyria, and severe liver disease 1

Remember that scalp fungal infections require systemic (oral) therapy, as topical treatments alone are insufficient for cure 1, 7.