|Year : 2000 | Volume
| Issue : 5 | Page : 238-240
A clinico - Mycological evaluation of onychomycosis
Vinod Sujatha, Sanjiv Grover, K Dash, Gurcha Singh
Source of Support: None, Conflict of Interest: None
Even though dermatophytes, especially Trichophyton rubrum, are most frequently implicated as the causative agents in onychomycosis, yeasts and moulds are increasingly recognised as causative pathogens. A study to analyse the morphological variants and mycological and cultural positivity of onychomycosis was carried out in 35 patients attending the Dermatology outpatient department of Command Hospital, Air Force, Banglore.
Keywords: Onychomycosis, Nail
|How to cite this article:|
Sujatha V, Grover S, Dash K, Singh G. A clinico - Mycological evaluation of onychomycosis. Indian J Dermatol Venereol Leprol 2000;66:238-40
|How to cite this URL:|
Sujatha V, Grover S, Dash K, Singh G. A clinico - Mycological evaluation of onychomycosis. Indian J Dermatol Venereol Leprol [serial online] 2000 [cited 2020 Jun 5];66:238-40. Available from: http://www.ijdvl.com/text.asp?2000/66/5/238/4932
| Introduction|| |
Onychomycosis refers to fungal infection of nails with various aetiological agents, involving dermatophytes, yeasts and moulds. It represents 18.4% of onychopathies and about 30% of mycotic cutaneous infections. 
Dermatophytes, especially Trichophyton rubrum are the most frequently implicated causative agents in onychomycosis. Previously regarded as contaminants, yeasts are now increasingly recognized as pathogens in finger nail infections, as are some moulds.  In view of this, a study was carried out to analyse the common morphologic pattern of onychomycosis and to evaluate the mycological and cultural positivity.
| Materials and Methods|| |
Patients with clinical features of onychomycosis, attending the Dermatology out patient department of Command hospital, Air Force, Bangalore from September 1997 to June 1998 were included in the study.
A detailed history with particular emphasis on history of trauma, infections, occupation, diabetes mellitus and personal habits were taken.
The morphological types of onychomycosis were documented as DLSO, PSO, SWO & TDO. All of them were examined for evidence of other fungal infections or coexistent cutaneous diseases.
Hematological and urine examination and blood sugar estimation were done in all cases.
Nail clippings treated with 10% KOH for 24 hrs were examined under light microscope for the presence of fungal mycelia and spores. Fungal culture of the nail material was done on Sabourauds peptone glucose agar, with cycloheximide, chloramphenicol and gentamicin in all cases.
| Results|| |
The age of the patients studied varied from 22-68yrs. 18 patients (51.43%) were within 20-40 yrs of age, 3 (8.5%) within 41-50yrs, 7(20%) within 51-60 yrs and 7 from 61-71 yrs age group.
The study group comprised 20 males and 15 females in the male to female ratio of 1.33: 1.
Duration of the disease at the time of presentation varied from 2 months to 3 years. 24 patients (68.57%) had complaints of < 1 year duration, 6(17.14%) had complaints of 1-1'/ 2 years, 3 (8.58%) had 1 1 /2 2 years and 2(5.71%) had>2 years duration of complaints [Table - 1]
Finger nails only were involved in 17 cases (48.57%), toe nails only were involved in 11 (31.43%) cases. Both toe and finger nail involvement were present in 7 cases (20%). DLSO was the commonest morphological pattern seen in 32 (90.57%) cases, followed by PSO in 6 cases (17.14%). TDO was observed in 3 cases (8.58%), paronychia in 2 (5.71%) cases and SWO in 1 (2.86%) case respectively [Table - 1].
Right thumb was the commonest finger nail involved and it was seen in 17 cases (48.5%). Among the toe nails rt. big toe nail involvement was the commonest, which was observed in 14 (40%) cases.
KOH smear examination of nail material under microscope was positive for fungal filaments in 27 (77.14%) patients. 2 (5.71%) patients showed spores and pseudomycelia, indicating the presence of candida. In 6 patients (17.14%) the smear was negative [Table - 2].
Culture of nail material revealed growth in 21 (60%) samples. Aspergillus niger was grown in 10 (28.57%) cultures, Z. rubrum in 6 (17.14%), E. floccosum in 3 (8.58%) and Candida albicans in 2 (5.71%) cultures each. 14 (40%) patients had no growth on culture.
7 (20%) cases had associated diabetes mellitus. Tinea pedis was co-existent in 5 (14.29%) cases, and Tcruris and Tmanum in 3 (8.58%) cases each. There were no immuno compromised cases.
| Discussion|| |
Recently there had been a noticeable worldwide increase in the incidence of onychomycosis. This has been related to a variety of aetiologic factors, including the rise in immunocompromised patients, an aging world wide population and a rise in environmental risk factors secondary to life style changes. 
Prevalence of onychomycosis has been reported to increase with advancing age. 15-20% of the occurrence is found in patients aged 40-60 yrs and the incidence rises in those over 60 yrs of age.  In our study 18 patients were within 20-40 yrs age group (51.43%). This increased incidence in younger population could be because they are more often exposed to occupation related trauma, predisposing them to onychomycosis. They may also be comparatively more cosmetic conscious than the older age group.
Various studies have shown no sex differences in the prevalence of onychomycosis.  A higher incidence in males in our study may be because of the result of increased trauma and the greater use of occlusive footwear in males compared to females.
A high incidence of onychomycosis of the toe nails have been reported by various authors.  The increased incidence of finger nail involvement in our study may be because of the increased incidence of occupation related trauma or because the finger nail infection is more likely than the toe nail infection to arouse the patients concern, driving them to seek medical attention.
In the present study, the big toe nail was the commonest toe nail involved. This is in agreement with other studies  possibly because of its greater size predisposing to increased trauma.
The high incidence of DLSO pattern in our study (90.57%) is in accordance with other studies also. ,
Our study revealed a mycological positivity of 82.82% on direct microscopic examination. Another study had reported a mycologic positivity of 63.3% in clinically suspected cases of onychomycosis. 
A 70% incidence of dermatophytes especially T.rubrum in the culture positive cases has been reported by some authors. , In our study, although dermatophytes have been isolated from 42.86% of culture positive cases, majority (47.6%) showed the growth of Aspergillus niger . This higher incidence of Aspergillus niger may not be significant, as these organisms are ubiquitous in nature and a common contaminant in cultures. 
Candida albicans is reported as the commonest cause of paronychial onychomycosis.  This is reflected in our study where all the paronychia cases grew Candida albicans on culture.
To conclude, our study has revealed a high relative incidence of male preponderance, finger nail onychomycosis, DLSO morphological pattern and T.rubrum among dermatophyte infections. However a longer study from a more representable population, preferably by including non-dermatology out patients, could reinforce or re-modulate the true picture of this fairly common condition.
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[Table - 1], [Table - 2]