Nail infections are commonly identified in both fingernails and toenails and are frequently difficult to treat. Infected nails can result in thickened, brittle, or discolored fingernails due to either fungal (onychomycosis) or bacterial (paronychia) pathogens in the nail bed, nail plate or the surrounding tissue. An injury or irritation can cause these infections to the nail or surrounding area and are frequently seen in patients with weakened immune systems, diabetes, or poor circulation.

Both fungal and bacterial nail infections rely on accurate clinical diagnosis to identify the pathogens present and will determine the success of the patient treatment plan. Conventional detection methods, such as culture and direct microscopy, are time-consuming, and many visual identification techniques often cannot identify nail pathogens in specimens. Nail culturing techniques are considered less sensitive than other detection methods and often depend on the amount of viable pathogen present in the sample and the success of growth in a culture environment. Direct microscopy of a sample is also considered less specific than other detection as it relies on a visual examination (potassium hydroxide (KOH)) of pathogens present. The accuracy of test results using both nail culture and direct microscopy detection also may be impacted by the current antibiotic or antifungal use of the patient.