By Dr Ananya Mandal, MD
Fungal nail infections, or onychomycosis, are commonly seen among the elderly and those with certain chronic health conditions. This includes those with Diabetes, psoriasis, peripheral vascular disease and those with suppressed immunity like with AIDS and cancers. (1-4)
Fungal nail infection and diabetes
This is the single most common cause of increased risk of fungal nail infections. Fungal nail infections accounts for up to half of all nail disease occurrences among diabetics.
Diabetics are 2.8 times more likely than non-diabetics to get fungal nail infections. The prevalence of dermatophyte onychomycosis is 13% in the United States. With age the incidence rises.
Less than 1% of the affected are below 18 years of age and nearly half of the affected are over 70 years. Fungal nail infections lead to pain, nail pressure, shoe and walking discomfort and embarrassment.
Patients need frequent visits to the podiatrist or physicians for their condition. Diabetics are also at risk of developing superimposed or secondary bacterial infections of the toes and fingers.
There may be foot ulcerations in 19% diabetics. Among these patients, need for amputation of the toes or limbs ranges from 6% to 43%, depending upon the severity of the ulcer.
In these patients with amputation the risk of dying in 5 years after the operation varies between 39% and 68%. The risk of fungal nail infections and ulcerations in diabetics is due to three pathological features. These include neuropathy, angiopathy and immunopathy.
Neuropathy signifies damage to the nerves or the fingers and toes due to long standing diabetes. It leads to unawareness of minor injuries to the foot or fingers and their nails that may predispose to nail infections and skin infections.
Angiopathy refers to poor blood circulation in the toes and fingers. This leads to inability of the blood to bring back the harmful toxins from the tips of the fingers and toes and similar inability of the blood to take the infection fighting white blood cells to the tips of the fingers and toes leading to increased propensity for infections.
Immunopathy also refers to suppressed immunity leading to a higher risk of fungal nail and skin infections. (1)
Fungal nail infections and psoriasis
Psoriasis is associated with nail changes of its own. In many psoriatic patients there is seen an increased propensity for nail infections with fungi.
Psoriatic nail disease may be a predisposing condition for invasion by the fungi. Because of the psoriatic damage to the nails, often fungal infections may be missed clinically. (2)
Fungal nail infections and allergic disorders
Patients with allergic disorders like long standing asthma, urticarial or hay fever and propensity to get hives and those with angioedema are at a higher risk for fungal nail infections.
Research suggests that there may be an allergic reaction to the fungus that causes risk of fungal nail infections in these individuals. (3)
Fungal nail infections and immunity suppression
People with immunity suppression like those with HIV infection and AIDS are at risk of fungal nail infections.
Treatment of cancer with chemotherapy and radiation therapy also reduces the immune functions and leads to a raised risk of fungal nail, hair and skin infections.
Those with rheumatoid arthritis are also at a raised risk of fungal nail infections due to altered immune system. (3)
Fungal nail infections and other fungal skin infections
Patients with other fungal skin infections like athlete’s foot etc. are at a raised risk of fungal nail infections.
These skin infections tend to recur and persistence of the fungal spores raise risk of fungal nail infections. (3)
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Jul 22, 2012