White superficial onychomycosis (WSO) is caused by fungal invasion of the superficial layers of the nail plate to form "white islands" on the plate. It accounts for around 10 percent of onychomycosis cases. In some cases, WSO is a misdiagnosis of "keratin granulations" which are not a fungus, but a reaction to nail polish that can cause the nails to have a chalky white appearance. A laboratory test should be performed to confirm.
Onychomycosis (toenail fungus) is an infection of the nail and sometimes surrounding tissue. It is extremely common with 20 percent of the general population and 75 percent of people over 60 years old affected. Frequently the problem causes cosmetic concerns, but many patients also experience pain. Sometimes toenail fungus can allow more serious infections to develop.
If you have diabetes, you may have reduced blood circulation and nerve supply in your feet. You're also at greater risk of a bacterial skin infection (cellulitis). So any relatively minor injury to your feet — including a nail fungal infection — can lead to a more serious complication. See your doctor if you have diabetes and think you're developing nail fungus.