Learn the 4 Types of Fungal Nail Infection

Learn the 4 Types of Fungal Nail Infection

Fungal nail infections come in 4 major types, and are named for where on the nail the infection originates. Nail fungus is commonly caused by microbial fungi called dermatophytes, but can also be caused by yeasts and non-dermatophyte molds. Learn about the 4 main types of fungal nail infections below:

#1 - Distal Lateral Subungual Onychomycosis (DLSO)

Distal lateral subungual onychomycosis, or "DLSO," is the most common type of nail fungus. Caused by the dermatophyte trichophyton rubrumwhich is also responsible for athlete's foot. DLSO infects the nail bed, as well as the nail, usually beginning at the end of the nail bed and working its way in. In most cases, the nail becomes noticeably yellow and opaque in appearance. As the infection progresses, debris builds up underneath the nail in the nail bed, the nail thickens and becomes brittle, and may become itchy and painful to the touch. The nail may start to crack, crumble, or chip, exposing the nail bed and preventing a healthy nail from growing in its place.

Distal Lateral Subungual Onychomycosis

#2 - Proximal Subungual Onychomycosis (PSO)

Like DLSO, PSO is also caused by trichophyton rubrum dermatophyte. PSO attacks the base of the nail, where the nail plate meets the skin, causing the skin to thicken and potential detach from the nail. Proximal subungual onychomycosis is the most rare type of onychomycosis, and is more common among patients suffering from HIV.

Proximal Subungual Onychomycosis

#3 White Superficial Onychomycosis (WSO)

White superficial onychomycosis is the second most common fungal nail infection behind DSO. Commonly caused by the dermatophyte trichophyton mentagrophytes, WSO attacks the nail plate, as opposed to DLSO which attacks the nail bed. This infection typically presents itself as a flaky white powder on the nail, and doesn't usually cause the nail to separate from the nail bed.

White Superficial Onychomycosis

#4 Candida Onychomycosis

Candida onychomycosis is a yeast infection of the nail, not caused by dermatophytes, but rather a strain of yeast called candida albicans. This infection is more rare than the previous, and more commonly affects fingers than toes. The yeast attacks areas of the nail that are weakened, and can present odd shapes and cause the nail to appear white, green, or brownish. This infection has a higher likelihood of becoming painful or sensitive, and may show signs of swelling and redness.

Candida Onychomycosis