A study on the etiological agent and clinico-mycological correlation of fingernail onychomycosis in eastern India

Abstract

Background:Onychomycosis manifests itself in various forms, notably onychodystrophy, onycholysis, subungual hyperkeratosis, or nail-plate discoloration. Not necessarily nail changes mentioned here should always be of fungal origin.Objective:The present study is planned to get an idea about etiological agent and clinical correlation in fingernail onychomycosis.Materials and Methods:Nail-clipping and subungual debris of patients with above mentioned nail changes were subjected to KOH preparation. Culture was done on SDA and SDCCA media. Species identification was done by colony character, pigment production, LCB staining, and some special tests like germ tube test, etc.Results:Out of 85 cases, 44 cases showed the growth of fungus, amounting to 51.76% positivity. Among those 44 cases, the infective fungal agents were predominantly dermatophytes (50%), and the rest were due to yeasts (27.27%) and moulds (22.72%). Among the different species, Trichophyton rubrum (29.54%) accounted for the majority of dermatophytes; Candida albicans (11.78%) was the predominant yeast; and Aspergillus niger (18.18%) the commonest mold. No significant association could be established between the different fungal species and various clinical manifestations. Positive results were found more with fungal culture (95.45%) than KOH preparation (63.64%).Conclusion:The results show that nail changes are not always a reliable marker for predicting the causative organism, and relying only on the clinical manifestation (i.e., pattern of nail changes) in the diagnosis of onychomycosis is often misleading. The present study highlights the need for microbiological confirmation in case of onychomycosis.

Non dermatophytic molds causing onychomycosis: a rising trend in North India

“…In studies which were conducted by Lone et al in Kashmir, Aghamirian et al in Iran, Kaur et al in New Delhi, Das et al in Kolkata and Jesudanam et al in Vishakhapatnam, 60%, 40.2%, 54.5%, 51.76% and 45.53% samples respectively were found to be positive by direct examination and/or culture. 9,14,[16][17][18] In our study, culture positivity (79%) was more than microscopy (63%), similar to another study conducted by Das et al in 2008 in Kolkata, where 32.9% were positive by direct microscopy and 49.4% by culture. While, studies conducted by Lone et al in 2013 and Shenoy et al in 2008 found more positivity by direct microscopy than culture, with a positive result by microscopy in 56% and 53% and culture positivity in 40% and 35% respectively.…”

The Prevalence of Fungi in Fingernail Onychomycosis

“…In the present study, 20% samples were identified as false negative (KOH negative and culture positive). False negative findings had also been observed in previous reports [5,7,14].…”

“…There is a long list of fungi which have a tendency to damage the nail, like dermatophytes (50%), yeasts (27%) and molds (23%) [7]. However, all the nail diseases are not fungal in origin they are also caused by other clinical conditions [6] like trauma, wet work (with the hand submerged in water) [8], HIV-AIDS [6], immunodeficiency which is due to organ or bone marrow transplantation [6], old age, psoriasis, atopic dermatitis [9], diabetes with a predominance of Candida spp [10], renal transplant recipients [11], etc.…”

A clinico-mycological study of onychomycosis at a tertiary care center

“…19 In our study yeast OM was high at 30.8% followed by DLSO (Distal Lateral Subungual Onychomycosis) and TDO (Total Destructive Onychomycosis) in 20.5% each. In our study we have also included cases which were also positive for yeasts in direct microscopy despite of them being negative in culture.…”

“…Some studies have not found diabetes as co-morbidity in OM. 11,19 In our study also it was not found to be significantly associated with OM when compared to the fungus negative group. On other hand, Onychomycosis has been found to be more common in diabetic patients than in non-diabetics by another study.…”