Oklahoma Cosmetology Board Practice Exam

Onychomycosis unguium is a fungal infection of the nail that affects the nail itself, not the surrounding skin (option D), the cuticle (option A), or the shape of the nail (option B). This infection can lead to discoloration, thickening, and brittleness of the affected nail. If left untreated, it can also spread to other nails and cause discomfort or pain. However, it does not affect the structural shape of the nail. Therefore, the most accurate answer is option C.