INTRODUCTION

Onychomycosis is a fungal infection of nails caused by dermatophytes, non-dermatophytes and yeasts.it affects approximately 5% of the population worldwide [1] and represents around 30% of all superficial fungal infection [2] and 50% of nail disorders [3].

Onychomycosis is often primarily a cosmetic problem, but it is actually a debilitating disease. It has negative physical and psychological effects on the patient. Therefore, it is very important to treat fungal nail diseases [4–6].

Nail changes in onychomycosis can occur in various forms onychodystrophy, onycholysis, subungual hyperkeratosis and discoloration or thickening of nail plate [7].

The fingernails onychomycosis is commonly seen in females as they more likely exposed to water and chemical detergents during daily domestic work whereas toenail infections was commoner in males due to prolonged use of closed footwear and increased physical activity [8].

The clinical presentations of onychomycosis are Distal Lateral Subungual Onychomycosis (DLSO), Proximal Subungual Onychomycosis (PSO), White Superficial Onychomycosis (WSO), and Total Dystrophic Onychomycosis (TDO) [9].

Direct microscopy using KOH preparation plays an important role in diagnosing nail fungal infections. However, fungal culture is the only definitive test that can be used to identify the species of the infectious organism [10].

Fungi causing onychomycosis to vary with the geographical distribution and differ from one country to another according to temperature and lifestyle of these countries [10,11].

Dermatophytes particularly Tricophyton rubrm and Trichophyton mentagrophytes represent 90% of toenail fungal infection and 50% of fingernail onychomycosis [12].

Candida species are second in frequency to dermatophytes as causative agents of onychomycosis. They constitute 10%-32% of toenail onychomycosis and 51%-70% of fingernail infections [13].

Non-dermatophyte molds are saprophytic non keratinolytic fungi that live in the soil and may be primary or secondary pathogens of the skin and nails. Previous nail destruction by a dermatophyte, trauma, or another nail disease favors nail infection by NDMs. The widespread use of broad-spectrum antibiotics, corticosteroids and other immunosuppressive drugs increase the incidence of nail infection due to NDMs [14].

MATERIALS AND METHODS

RESULTS

Out of a total of 135 patients, 119 were diagnosed with onychomycosis based on culture and, or direct microscopic examination. Of these 119 patients 96 (80.7%) were females and 23 (19.3%) were males. The mean age of patients with onychomycosis was 40.7± 14.34years. Onychomycosis was most prevalent in the age 30-39 years age group, with a female: male ratio of 4.2:1 (p= 0.013) demonstrating statistically significant association between age and sex (Table 1).

Fungal culture was positive in 111 (82.2%) specimens (Table 2). Direct microscopic examination was positive in 50 (37%) specimens and negative in 85(63%) specimens and positive direct microscopic alone in 8 (33.3%) of cases (Figs 1a and 1b).

Fingernails were involved in 78 (65.5%) cases, toenails in 22 (18.5%) cases and both fingernails and toenails were affected in 19 (16%) cases. Fingernail involvement was statistically significant in women (p= 0.001) while toenail involvement was statistically significant in men (p= 0.001) (Table 3). Distal lateral subungual onychomycosis (DLSO) was the most common clinical type observed in 33 (42.3%) (Fig. 2a) in fingernails and 10 (45.5%) in toenails, followed by proximal subungual onychomycosis (PSO) in 24 (30.8%) of fingernails (Fig. 2b) and 6 (27.3%) of toenails.

White superficial onychomycosis was observed in 11 (14.1%) in fingernails and 3 (13.6%) toenails (Fig. 3a). total dystrophic onychomycosis was observed in 10 (12.8%) in fingernails (Fig. 3b) and 3 (13.6) in toenails (Table 4). Candida and non-dermatophyte molds were the most frequent causative agents in 37% each (Table 5).

Among yeasts were the common causative agents isolated Candida albicans (Figs 4a and 4b) was observed in 19 (46.3%) followed by Candida parapsilosis complex in 15(36.7%), and Candida tropicalis observed in 7 (17%).

Among non-dermatophyte molds, Aspergillus nigra (Figs 5a and 5b) was the most common isolate observed in 15 (36.7%), followed by Penicillium spp. (Figs 6a and 6b) in 7 (17.1%). Others non-dermatophytic strains were isolated Aspergillus flavus (14.6%), Fusarium spp. (9.8%), Scopulariopsis spp. (9.8%), Alternaria spp. (7.3%), Chaetomium spp. (2.4%) and Cladosporium spp. (2.4%).

Among dermatophytes were the common causative agents isolated Trichophyton tonsurans (Figs 7a and 7b) was observed in 10 (34.5%) followed by Trichophyton verrucosum in 7 (24%) (Figs 8a and 8b).

Other dermatophytic strains were isolated, include Trichophyton violaceum (13.8%), Trichophyton soudanense (Figs 9 and 9b) (10.3%), Trichophyton mentagrophytes (7%), Trichophyton rubrum (7%), and Epidermophyton floccosum (3.4%).

DISCUSSION

Onychomycosis is a chronic infection of the nails, and is considered a serious problem for public health [15]. Onychomycosis has both psychosocial and physical detrimental effects on quality of life [16]. In the present study, onychomycosis was found to be common in the age 30-39 years (30.3%). similar findings also reported in studies from Saudi Arabia, Indonesia and India [17–19]. In contrast, some studies have reported that onychomycosis affected elderly individuals [20]. The increase in incidence of onychomycosis in younger population could be explained by the fact that they are more often exposed to occupation related trauma that predisposes them to infections and they may also comparatively more cosmetically aware than older age group. This study revealed that there was highly significant difference between male and female (p=0.001), that’s mean the females more affected than males and the female to male ratio was 4.2:1. This result was consistent with other studies, which reported a higher incidence in female [21]. In contrast to other studies who had reported males to be affect more than females [19]. Fingernail fungal infections were more common than toenail infections (65.5% and 18.5% respectively) and significant increase in incidence of finger nail onychomycosis among females than males 74% and 30.4% respectively (p=0.001). This difference may be explained by the work habits of female patients who perform domestic chores in some occupations, such as: cooking, washing clothes and floor cleaning, with wet hands for most of the day. In addition, this state of affairs is aggravated by the chemical action of detergents. These causal factors are supported by the large incidence of infection of the fingernails in women (74%) compared to those of men (30.4%). This result was consistent with other studies, which reported a higher incidence in female [21–23].

Toe nail onychomycosis was more affecting male patients than female patients,47.9% and 11.4% respectively, and this difference was highly significant (p = 0.001). This could be explained by religious (Muslim) practice of washing the feet five times daily may be a possible rout of fungal infection of toenails (19), and the difference between male and female could be due to the difference between male and female in the life style and type of work, which lead to more toenail trauma in males that led to secondary fungal infection. This finding was reported with observation of P veer et al. who reported that toenails involvement was more frequent in males than females [24].

The most common variety of onychomycosis, distal lateral subungual onychomycosis (DLSO), is characterized by invasion of the nail bed and underside of the nail plate. The high incidence of DLSO pattern (33.6%) followed by PSO (23.5%), in current study was in accordance with other studies [19,25].

Direct microscopy using KOH preparation plays an important role in diagnosing nail fungal infections. However, fungal culture is the only definitive test that can be used to identify the species of the infectious organism [10]. In the present study, fungal culture growth was reported in 82.2% of cases while no growth was observed in 17.8% of cases. These results are relatively similar to those results reported by; EL-Hamed et al. [26] who obtained positive culture for fungi in 80.9% of cases and no growth observed in 19.1% of cases.

In our study, yeast and non-dermatophyte molds were the most common causative agents each accounting for (37%) of cases while dermatophytes were isolated in (26%) of cases. Similar other studies have also reported yeasts and molds as the predominant pathogens involved in onychomycosis [23,27]. Among the yeasts, Candida albicans were the most common isolates in (46.3%) of cases followed by Candida parapsilosis complex in (15%) of cases. Similar findings reported in Tunisia [28], candida albicans accounted for (55.6%) and candida parapsilosis (8.2%) of candida nail infections. A high isolation rate of NADs was observed in current study (37%). Similar high the isolation in Malaysia (45.4%) and Teheran (40.5%) [10,14]. In contrast studies where the isolation rate of NDMs varied from (1.49%) and (33%.5) [29,30]. This variation may reflect geographic differences in molds distribution and humidity. In addition, use of broad-spectrum antibiotics, and immunosuppression drugs.

Among NDMs isolates, Aspergillus nigra was the commonest fungal isolate (36.6%), followed by Penicillium spp. (17.1%). Meanwhile in the study from Egypt, it has been reported that Aspergillus Niger is the commonest fungal isolates from nail disorder [31]. Other non-dermatophytic strains were isolated Aspergillus flavus (14.6%), Fusarium (9.8%) Scopulariropsis spp. (9.8%) Alternaria alternate (7.3%), Chaetomium spp (2.4%) and Cladosporium spp (2.4%). These results were relatively similar to those results reported from other parts of the world, such as Cameroon [32], and Italy [33]. Dermatophytes are hyaline septated molds. The hyphae of these mycelial organisms penetrate the stratum corneum of the skin and nails. The fungal cells manufacture keratinolytic protease, which provide a means of entry into living cells [34].

Trichophyton rubrum was reported as the most common causative agent of onychomycosis in Senegal (53.6%) and France (85.1%) [35,36].

In the present study, Trichophyton tonsurans (34.5%) was the common pathogenic dermatophyte isolated followed by Trichophyton verrucosum (24%) and Trichophyton rubum (7%). These findings were not in agreement with those of another study, in which Trichophyton rubrum was the predominant spices (23%) followed by Trichophyton tonsurans (8.85%) and Trichphyton verrucosum (3.54%) [37]. This variation may be attributed to differences in geographical location, climatic conditions and population habits which may influence the distribution of dermatophyte spices. Other dermatophytic strain were isolated Trichophyton violaceum (13.8%), Trichophyton soudanense (10.3%), Trichophyton mentagrophytes (7%), and Epidermophyton floccosum (3.4%) of cases. These results support our observation that T.tonsurans and T verrucosum may play a significant role in onychomycosis in our region, possibly influenced by local environmental and occupational factors.

CONCLUSION

Onychomycosis is a common disease in our place and constitutes major health problem that profoundly affect the patient quality of life and functional activity. Onychomycosis was predominately seen in females with high frequency among the age group 30-39 years and DLSO was the most frequently clinical types found in both fingernails and toenails followed by PSO.

Although the causative agents of fungal infection are changing from time to time and from place to another, at present our study, showed that the common pathogenic organism causing onychomycosis in our area were candida albicanis and non-dermatophyte molds (Aspergillus nigra), followed by dermatophyte (T. tonsurans and T. verrucosum).

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