Acute onychomycosis should be treated effectively as soon as possible to prevent nail bed damage. A broad-spectrum antibacterial agent with an antibacterial spectrum covering both aerobic and anaerobic bacteria, such as amoxicillin/clavulanic acid, may be used. If symptoms do not improve within 48 hours, surgical treatment should be instituted. Chronic onychomycosis is treated with antifungal drugs (azoles are preferred) or antibacterial drugs as needed, and treatment needs to continue until the inflammation subsides and the nail tubercle rebuilds and adheres to the nail plate, often for more than 3 months. In patients with recurrent acute exacerbations, treatment with intra-dermal or systemic glucocorticoids in combination with systemic antimicrobials may be instituted for 1 week. Chronic onychomycosis caused by cetuximab may be treated with oral doxycycline at 100 mg twice daily.