Detection of Dermatophyte in Sub-clinically Involved Nails by PCR in Patients With Skin Dermatophytosis

Dermatophytic infection of skin has become anincreasing and common problem in population and are found in keratinized layersof skin, nail and hair causing superficial mycoses. Dermatophytic infection of skinis easy to diagnose clinically and microbiological diagnosis is important toconfirm the etiology before starting the treatment. Diagnosis can be confirmedby microscopy and culture. Microscopic examination of the skin scrapping andthe nail can be performed as an outpatient basis but has low sensitivity. Culture of the fungus takes 4-6 weeks because of the slow growth of theorganism.  Molecular methods using RTPCRhas been developed to overcome this problem. The dermatophyte can rapidly bediagnosed by RT-PCR as they have the advantage of high sensitivity andspecificity and faster turnaround time over the other conventional methods andis more accurate for the diagnosis.

 Patients with extensive dermatophytic infection of theskin can have dermatophytes in the nails due to chronic itching which can beeasily missed on clinical examination. These patients may not respond totreatment with conventional dose and duration of antifungals used and they mayhave periodic recurrences.

 In such patients, microscopy with potassium hydroxide(KOH) and culture may not reveal the dermatophytes due to poor sensitivity,specificity and so, the detection of the dermatophytes in the nails are oftenmissed.

In such patients, PCR being more sensitive andspecific can be a better technique to detect the fungus in the nail.

So, we plan to conduct a study to detect dermatophytesin patients with uninvolved nails by PCR in people who are having KOH-positiveskin dermatophyte infection.