• Distal subungal onychomycosis is by far the most common fungal infection of the nails, causing an estimated 90 percent of all cases. This type of fungus usually affects both the nail and the skin underneath it, and is more common in toenails than in fingernails. The infection often starts as a discoloured area in the corner of the big toe and then spreads slowly toward the cuticle. Other symptoms include pit marks, yellow streaks in the nail bed and underneath the nail, discolouration, and a thickening of the nail that may become flaky and separate from the nail bed. Debris that gets trapped underneath the nail may cause the nail to become brown and foul-smelling. The infection can also result in brittle nails that become soft and begin to crumble.
• Proximal subungal onychomycosis is similar to the distal type but starts at the cuticle and slowly spreads toward the tip, causing the nail to rise. This type of nail fungus is very unusual and typically occurs in people with compromised immune systems.
• White superficial onychomycosis is a fungal infection that causes white spots or streaks on the nail surface, which could turn soft, dry and powdery as the infection progresses. Eventually the nail may become damaged, crumbly and brown or gray, but unlike the distal type the nail does not separate from the nail bed.
• Yeast onychomycosis is caused by the yeast Candida. Yellow, brown, white or thickened nails are common symptoms of nail infections caused by yeast. Some people with Candida in the nail also have a yeast infection in the mouth or suffer from chronic paronychia, one of the most common types of skin infections.

If you have brittle, peeling or split nails mainly because of environmental factors, some simple lifestyle changes could help improve the problem. For example, avoid soaking your hands and feet in water for extended periods of time, and make sure to dry them thoroughly after they have been wet. Use a mild soap and do not wash your hands excessively. Also try to avoid exposing your nails to chemicals, such as harsh nail polish removers, and moisturize them daily.

But if a nail fungus or nail psoriasis is to blame for your dry and brittle nails, you will need additional treatment to get rid of the infection, and the sooner you start treatment the better. For mild to moderate cases of onychomycosis there are several over the counter creams, ointments and nail lacquers available. Another option is Naloc, a topical treatment that treats nails affected by fungal infection or psoriasis. It also improves the appearance of discoloured and deformed nails. Naloc increases hydration, gently smoothes the outer layers of the nail plate and, by changing the nail’s microenvironment and improving nail surface integrity, keeps nails in good condition. First signs of improvement are normally seen already after 2-4 weeks of treatment

For severe nail infections, a topical antifungal treatment may not suffice and your doctor may recommend oral medications, removal of the nail or laser treatment. Although there is no cure for nail psoriasis, severe cases are sometimes treated with steroid injections. 

Treating nail fungus and nail psoriasis is challenging and regardless of which treatment you choose, complete healing could take up to six months for a fingernail and a year for a toenail.