Treatment of Pityriasis Versicolor Resistant to Topical Antifungals
For pityriasis versicolor that is not responding to topical antifungals, oral fluconazole 400 mg as a single dose is the most effective treatment with the highest cure rate and lowest relapse rate over 12 months. 1
First-line Systemic Treatment Options
When topical antifungals fail to treat pityriasis versicolor (tinea versicolor), systemic therapy becomes necessary. The following options are recommended:
Oral fluconazole 400 mg as a single dose - Provides the best clinical and mycological cure rate (80% and 82.2% respectively) with no relapses during twelve months of follow-up 1
Oral fluconazole 150 mg once weekly for 4 weeks - Alternative regimen with 59.9% clinical cure and 64.4% mycological cure at 4 weeks 1
Oral itraconazole 200 mg daily for 5-7 days - Effective alternative with a total dose of 1000 mg required for effective treatment 2
Oral itraconazole 200 mg daily for 10 days - Another effective regimen with 73.3% clinical cure and 73.3% mycological cure at 4 weeks 1
Comparative Efficacy
Fluconazole has demonstrated superior efficacy compared to ketoconazole in treatment of extensive pityriasis versicolor, with fewer hepatotoxic effects 3
Single-dose fluconazole 400 mg shows better long-term outcomes than single-dose ketoconazole 400 mg, with no relapses over 12 months for fluconazole compared to maximum relapses with ketoconazole 1
Terbinafine, while effective for other dermatophyte infections, appears to be ineffective for pityriasis versicolor when taken orally 4
Treatment Considerations
Assessment of treatment response should be done at 2-4 weeks after treatment, as the dead organisms disappear slowly from the skin 2
For extensive cases (body involved area ≥25%), systemic therapy is more suitable than topical treatments 3
Predisposing factors should be addressed to prevent recurrence, including high temperatures, high humidity, greasy skin, hyperhidrosis, corticosteroid treatment, and immunodeficiency 5
Prophylactic Treatment
A prophylactic treatment regimen is mandatory to avoid recurrence after successful treatment 5
For patients with frequent recurrences, consider maintenance therapy similar to that used for recurrent vulvovaginal candidiasis, such as fluconazole 150 mg once weekly for a period of time 6
Important Considerations
Malassezia (also known as Pityrosporum ovale or P. orbiculare) is the causative organism that changes from blastospore to mycelial form under the influence of predisposing factors 5
Diagnosis should be confirmed by KOH examination and Wood's lamp before initiating systemic therapy 1
Oral antifungal therapy should be considered the primary treatment for cases that have failed topical therapy, as it reduces the number of Malassezia and increases the time to recurrence 5