Dermatophytosis caused by Trichophyton species is a common superficial fungal infection of the skin, hair, and nails. Increasing reports of persistent or recurrent disease after standard antifungal therapy have raised concern for treatment resistance and incomplete clearance of fungal elements from keratinised tissues. Itraconazole is a widely used systemic antifungal for Trichophyton infection, however relapse after treatment can occur. Isotretinoin is an oral retinoid that reduces skin oil production and modifies keratinisation, and it may change the skin environment in a way that helps prevent persistence or recurrence of dermatophyte infection. This study will compare a combination regimen of oral itraconazole plus oral isotretinoin with oral itraconazole alone in adults with laboratory-confirmed Trichophyton infection.

This comparative clinical study will be conducted in the Dermatology Department of Multan Medical and Dental College and Ibn-E-Siena Hospital and Research Institute. Adults aged 18 to 65 years with clinical features suggestive of dermatophytosis will be screened, and only participants with confirmed Trichophyton infection on potassium hydroxide microscopy and or fungal culture will be enrolled. A total of 148 participants will be randomly allocated in equal numbers to one of two groups. One group will receive oral itraconazole plus low-dose oral isotretinoin for the study treatment period, and the other group will receive oral itraconazole alone at the same itraconazole dose and duration. Use of additional systemic antifungals or systemic retinoids during the treatment period will not be permitted.

The primary purpose is to determine whether adding isotretinoin to itraconazole improves treatment effectiveness and reduces recurrence. Outcomes will include clinical cure at the end of treatment, mycological cure based on negative potassium hydroxide microscopy at the end of treatment, time to symptom resolution, and relapse within the predefined follow-up period, assessed during scheduled follow-up visits. Safety will be monitored at each visit, including adverse drug reactions and laboratory testing as required. Liver function testing will be performed for all participants, lipid profile monitoring will be performed for participants receiving isotretinoin, and pregnancy testing and counselling on strict pregnancy avoidance will be provided for women of childbearing potential due to the known risk of fetal harm with isotretinoin.

Inclusion Criteria:

• Age 18 to 65 years
• Clinical features suggestive of dermatophytosis
• Laboratory-confirmed Trichophyton infection at baseline
• Provision of written informed consent
• Ability and willingness to comply with treatment, follow-up visits, and required laboratory monitoring

Exclusion Criteria:

• Negative potassium hydroxide microscopy and no culture evidence of Trichophyton infection at baseline
• Infection caused by non-Trichophyton dermatophytes on culture, or no growth on culture where culture is used for confirmation
• Use of additional systemic antifungal therapy during the treatment period (not permitted by protocol)
• Use of systemic retinoids other than study-assigned isotretinoin during the treatment period (not permitted by protocol)
• Pregnancy at baseline in women of childbearing potential, or inability or unwillingness to follow strict pregnancy avoidance requirements during and after isotretinoin therapy
• Any contraindication to itraconazole or isotretinoin, including known hypersensitivity to either drug
• Clinically significant baseline liver dysfunction or abnormal liver function tests considered unsafe for systemic itraconazole and or isotretinoin use