Diabetes mellitus, immunosupression ve steroid uptake cause dermatophyte infections to progress more generalized and severe. Cases of tinea corporis caused by Tricophyton rubrum were described in immunosupressive as well as psoriatic patients. The female patient using long term methotrexate and systemic steroid treatment for psoriasis and psoriatic arthritis, with diabetes mellitus was diagnosed as tinea corporis due to Microsporum audouinii and presented to be rare.