Fungal nail infections can be caused by a variety of species of fungi; aspergillus nail infection (onychomycosis) is a relatively unusual type caused by an environmental fungus. There are many different species of Aspergillus fungi – they grow on decaying plant and animal matter in nature and disperse their spores throughout the natural world. As well, aspergillus thrives in human environments: in moist damp cellars, sheds and barns, on moldy food, straw, grains, and in fields where plant stubble is decomposing. We come in contact with aspergillus spores constantly. Usually the mold is not a health problem; however, occasionally inhalation of spores causes fungal lung infections, and contamination of nails can result in onychomycosis.
Aspergillus onychomycosis is generally a distal subungual infection: it starts under the nail near the tip of the finger, where spores may have lodged under the nail or at the sides where the nail creases the skin. Once the fungus starts to grow, the infection spreads back toward the cuticle. It looks much the same as any fungal nail infection, discoloring the nail, causing it to become thick, distorted and flaky. The fungus will not, however, spread to the surrounding skin like some other fungal causes of nail infection. Aspergillus species growing in nature often produce colorful pigments; therefore, an aspergillus nail infection may well appear greenish, black, brown or various other shades.
It is not possible for a doctor to diagnose aspergillus onychomycosis just by looking at the affected nail. Only about half of nail diseases are caused by fungi, and only a small percentage of those are aspergillus nail infection: onychomycosis is more often caused by one of the dermatophytes (fungi that grow on skin) – Trichophyton rubrum, T. mentagrophytes, and others. To determine what species of fungus, if any, is responsible, a nail sample must be cultured in the laboratory and any fungal growth identified by experts.
An aspergillus nail infection can be treated in the same way as any other fungal nail infection. It should be remembered however, that aspergillus may not be one of the fungi that drug manufacturers and producers of antifungal alternative remedies have tested their formulations against. Testing of antifungals is usually done using the most common causes of the infection and aspergillus onychomycosis is relatively unusual. This may explain some treatment failures so often reported for nail fungus treatments.