Onychomycosis: A significant medical problem

Introduction

Onychomycosis accounts for upto 50% of all nails problems. [1],[2] At least 15% to 20% of persons between 40-60 years of age may have this disease. In addition, immunocompromised persons, diabetics, and athletes are also considered to be at risk.

The purpose of this study is to document the incidence, prevalence, contributing factor, associated diseases, the common types and the causative agents of onychomycosis and also to observe the psychosocial and occupational consequences of onychomycosis among patients attending Dermatology outpatient department.

Materials and Methods

During the period between November ′98-October ′99 nail samples were obtained from 448 patients with nail abnormalities from among 21, 373 patients who attended the Dermatology out patient department of King George Hospital, Visakhapatnam (A. P). The affected nails were thoroughly washed with 70% alcohol and the material was collected onto a sterilised paper using a sterile nail cutter or scraper. The samples were subjected to direct microscopy using 20% potassium hydroxide and the remaining material was cultured on Sabouraud′s dextrose agar with and without cycloheximide.

A detailed history of age, sex, occupation, duration of the disease, predisposing factors, associated diseases etc. , were recorded in all cases. Baseline investigations were carried out in all cases, while the diabetic and HIV status was established in all cases which were positive on microscopy or culture or both.

Results

Of the 448 patients with nail abnormalities, the diagnosis was confirmed in 204(45. 53%) by direct microscopy or culture or by both. These 204 patients constituted the study population. ln the present series 192 (94. 12%) patients were from rural areas [Table - 1]. The age of the patients varied from 5-72 years, majority (59. 8%) i. e. 122 out of 204 patients were between 21-40 years of age. 106 (51. 96%) out of the 204 patients were females, while 98(48. 04%) were males [Table - 1]. 98 (48. 04%) had occupations associated with wet work, 44 (21. 57%) had occupations associated with increased physical activity. Housewives formed a predominant group accounting for 33. 33% of the patients [Table - 2]. 19 (9. 31%), 8(3. 92%) and 23 (11. 27%) had a past history of T. pedis, T manuum and trauma respectively [Table - 3] The duration of the disease varied from 3 months to 15 years. More than 1/3rd(38. 23%) of the patients had the disease for less than one years 24(11. 76%) patients had diabetes mellitus and 2 (0. 98%) were tested positive for HIV antibodies. Recurrent episodes of mycotic infections of the skin were tested positive for HIV antibodies. Recurrent episodes of mycotic infections of the skin were recorded in 51 (25%) patients. Fungal infection over other sites of the body were seen in 43 (21. 07%) patients. Finger nails were affected in 117 (57. 35%) patients, toe nails in 66 (32. 35%) patients and both finger and toe nails in 21 (10. 29%) patients. Candidal onychomycosis was the most common clinical type (58. 82%) seen, followed by distal subungual onychomycosis (38. 72%). White superficial onychomycosis was seen in 3 (1. 47%) patients and proximal subungual onychomycosis in 2 (0. 98%) patients. Direct microscopic examination and culture on Sabouraud′s dextrose agar were positive in 190 and 178 cases respectively. The most frequently isolated fungus was candida in 101 (56. 74%) patients, followed by dermatophytes in 68 (38. 20%) patients and non-dermatophyte moulds in 6(3. 37%) patients. Candida species were predominantly isolated from the finger nails (75. 25%), while dermatophytes were isolated more frequently from the toe nails (60. 29%) [Table - 4]. Onychomycosis had a significant negative impact on quality of life, with 55 (26. 96%) patients experiencing physical, psychological, social or occupational problems. 44 (80%) out of these 55 patients had finger nail onychomycosis. Finger nail onychomycosis had a greater impact on the quality of life compared to toe nail onychomycosis [Table - 5].

Discussion

Onychomycosis is a chronic mycotic infection of finger nails and toe nails that affects the quality of life in a significant proportion. There has been a recent increase in the incidence as well as the spectrum of causative pathogens associated with onychomycosis. This increase in the incidence can be attributed to various factors like an aging population, an ever expanding number of immunocompromised patients and life style practices. [4]

Onychomycosis occurs worldwide. Onychomycosis appears to be a variable entity presenting in different forms in different part of the world with every country and every region of the same country having its own characteristics of presentation. [5] The prevalence of onychomycosis in our hospital based study was 0. 95%. Eleweski, [6] from U. S. A. estimated the prevalence to be between 8-9% of the total population while Evans. [7] and Robert, [8] from United Kingdom reported a prevalence of 5% and 2. 7% respectively in the general population. The fact that not all patients affected by onychomycosis seek medical assistance, can also explain the differences in prevalence of onychomycosis observed worldwide. [5] The commonest age group affected in our study was 21-30 (33. 33%) years followed by 31-40 years (26. 47%). A similar high incidence among 21-30 years age group was reported by Reddy, et al. [9] In contrast, Mercantini, et al, [10] Velez et al, [11] reported a higher prevalence among adults over the age of 50 years. Increased participation in physical activity, increased exposure to wet work, shoe wearing habit among this age group and early marriage leading to new household responsibilities could be some of the contributing factors for the increased prevalence in the 21-30 years age group.

In our study there were more women (51. 96%) than men patients (48. 04%) Mercantini, [10] Lopes, [12] and Bokhari, [13] also reported a higher prevalence of 72. 1%, 62. 7%, 72% respectively among women. In contrast, Reddy, et al[9] reported a higher prevalence among men (68. 9%). Domestic activity involving wet work associated with constant trauma to the nails could probably explain the slightly higher prevalence among women. 48. 04% of our patients had occupations associated with wet work making them more prone to develop candidal paronychia and candidal onychomycosis, while 21. 57% had occupations associated with increased physical activity with trauma facilitating easy entry of fungal pathogens. Finger nails (57. 35%) mainly of the right hand especially the thumb finger (18. 62%) were more frequently involved than toe nails in both sexes. Reddy et al[9] Velez et al[11] Rigopoulos, et al, [5] also reported an increased involvement of the nails. In our country finger nails especially the thumb nails is used as a multipurpose tool for jobs such as peeling vegetables, feeding children etc., making them more prone to injuries and infections. Open foot wear could explain the decreased incidence of toe nail involvement.

Candidal onychomycosis (58.82%) was the predominant clinical type and was seen among those whose occupations involved wet work. Distal subungual onychomycosis was the commonest type. Two out of three patients with superficial white onychomycosis had the habit of wearing shoes regularly, which supports the observations of English[14] that white superficial onychomycosis occurs in the toe nails of predominantly shoe clad population. Both our patients with proximal subungual onychomycosis, a marker for HIV, were tested positive for HIV antibodies. In areas of high HIV endemicity, onychomycosis is often recognised as a marker for HIV infection.[15] Reddy, et al.,[9] and Banerjee et al.,[16] from India reported distal subungual onychomycosis as the commonest type in their respective studies. Higher isolation rate of candida (56.74%) noted in this study was also reported by Achten.[17] AI-sogiar ,[18] Rigopoulos[5] and other workers from different parts of the world. In contrast Reddy,[9] Banerjee[16] from India, reported a higher isolation rate of dermatophytes in their respective studies.

In our study 26.96% of the patients experienced physical (18.62%) psychological (23.52%), social (10.29%) and occupational (5.88%) problems. Lubeck et al.[19] Drake et al.[20] have documented the negative impact of onychomycosis on patients quality of life. The importance of onychomycosis is often underestimated. Although not usually life threatening,onychomycosis can be a source of significant pain and discomfort, it can also pose risk for patients, their families and others in contact with them. Onychomycosis can no longer be considered a simple cosemetic nuisance confined to the nails. It is a significant and important disease which can generate many physical, psychosocial and occupational problems, considerably impairing patients quality of life.