Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Toenails or fingernails may be affected, but it is more common for toenails to be affected. Complications may include cellulitis of the lower leg. A number of different types of fungus can cause onychomycosis, including dermatophytes and Fusarium. Risk factors include athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, and poor immune function. The diagnosis is generally suspected based on the appearance and confirmed by laboratory testing.
Onychomycosis does not necessarily require treatment. The antifungal medication terbinafine taken by mouth appears to be the most effective but is associated with liver problems. Trimming the affected nails when on treatment also appears useful. There is a ciclopirox-containing nail polish, but it does not work as well. The condition returns in up to half of cases following treatment. Not using old shoes after treatment may decrease the risk of recurrence.
It occurs in about 10 percent of the adult population. Older people are more frequently affected. Males are affected more often than females. Onychomycosis represents about half of nail disease. It was first determined to be the result of a fungal infection in 1853 by Georg Meissner.
Following effective treatment, recurrence is common (10–50%). Nail fungus can be painful and cause permanent damage to nails. It may lead to other serious infections if the immune system is sup
Following effective treatment, recurrence is common (10–50%). Nail fungus can be painful and cause permanent damage to nails. It may lead to other serious infections if the immune system is suppressed due to medication, diabetes or other conditions. The risk is most serious for people with diabetes and with immune systems weakened by leukemia or AIDS, or medication after organ transplant. Diabetics have vascular and nerve impairment, and are at risk of cellulitis, a potentially serious bacterial infection; any relatively minor injury to feet, including a nail fungal infection, can lead to more serious complications. Infection of the bone is another rare complication.
Research suggests that fungi are sensitive to heat, typically 40–60 °C (104–140 °F). The basis of laser treatment is to try to heat the nail bed to these temperatures in order to disrupt fungal growth. As of 2013 research into laser treatment seems promising. There is also ongoing development in photodynamic therapy, which uses laser or LED light to activate photosensitisers that eradicate fungi.