3 groups of patients with onychomycosis will be recruited. Group A will receive itraconazole alone. Group B will receive itraconazole + low dose isotretinoin and group C will be treated with itraconazole + excimer light sessions.

The sample size will be calculated by a statistician based upon the rate of onychomycosis cases attending at the outpatient clinical. 3 equal groups of patients will be included. inclusion criteria include: -definite diagnosis of dermatophyte onychomycosis using KOH examination and a fungal culture - a washout period of at least 1 month of any previous therapy -age> 16 years Exclusion criteria include: -pregnancy and lactation -Any active infection or inflammation in or around the nails other than onychomycosis -patients with liver diseases, heart disease and diabetes

Steps of performance and techniques used:

1. Complete history taking.
2. Detailed local examination:

Local examination will be done for the nail to detect swelling, induration, erythema around the nail, local pain and presence of pus during the sessions.

Patients with proven onychomycosis clinically, dermoscopically and through culture will be included in the study.

The included patients will sign an informed written consent before the beginning of the study, and the study will be done under the approval of the ethical committee for postgraduate studies and research of faculty of Medicine, Zagazig University.

Onychomycosis severity index (OSI) will be used for grading of onychomycosis severity where 0=no onychomycosis,1-5= mild onychomycosis,6- 15=moderate onychomycosis, and 16-35=severe onychomycosis.

The patients will be divided into 3 equal groups:

GROUP 1: (itraconazole group); all patients will be prescribed Itraconazole in the dose of 200mg twice daily for 1 week per month, for 3 consecutive months after screening of complete blood count, liver, and renal function tests. patients were advised to record any side effects.

GROUP 2 : will be given low dose of isotretinoin as an adjuvant to itraconazole in the same previously mentioned protocol.

Treatment protocol consists of low dose isotretinoin 20mg, every other day for a 3- month course. After completion of the course, treating dose of isotretinoin will be maintained for 4-6 weeks to prevent recurrence, and to improve healing. During treatment, an infrequent application of the previous therapies will be permitted.

GROUP 3: will be treated with excimer light as an adjuvant to itraconazole in the same previously mentioned protocol. Nails will be treated with XeCl2 excimer light (Eximal Elite Device).

Inclusion Criteria:

• patients with onychomycosis

Exclusion Criteria:

• pregnant and lactating females patients on statin therapy or photosensitizing drugs patients with liver disease, heart disease and diabetes milletus.