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Journal of Pharmaceutical, Chemical and Biological Sciences ISSN: 2348-7658 Impact Factor (GIF): 0.615 Impact Factor (SJIF): 2.092 June-August 2015; 3(2):150-155 Available online at http://www.jpcbs.info

Review Article

Review on Onchomycoses: Definition, Causes, Treatment and Prevention Alaa M. Hasan

Department of Biology, Collage of Science, University of Baghdad, Iraq

*Corresponding Author: Alaa M. Hasan, Department of Biology, Collage of Science, University of Baghdad, Iraq

Received: 01 June 2015 Revised: 09 June 2015 Accepted: 11 June 2015

ABSTRACT

Onychomycosis is a fungal of the nail unit, more common in toenails than in fingernails, There are 4 to 5 subtypes related to the method of fungal invasion of the nail unit, the most common being distal lateral subungual . Onychomycosis can cause pain, discomfort, and disfigurement and may produce serious physical and occupational limitations, as well as reducing quality of life. rubrum is the most common involved in onychomycosis.

Other dermatophytes that may be involved are T. interdigitale, , T. violaceum, , T. tonsurans and T. soudanense. Candida spp. mainly causes fingernail onychomycosis in people whose hands are often submerged in water. Other more commonly affect people older than 60 years, and their presence in the nail reflects a slight weakening in the nail's ability to defend itself against fungal invasion.

Keyword: Onychomycosis; dermatophytes; Candida; antifungals and fungal infection

INTRODUCTION Onychomycosis is the most common nail infection that affects the toenails or the disease, accounting for about half of nail fingernails. Onychomycosis may involve any pathologies [1], if untreated, it can lead to pain, component of the nail unit, including the nail discomfort in shoes, infection, and subungual matrix, nail bed, or nail plate. Such infection ulceration. There may also be increased self- isnot life threatening, but it can cause pain, consciousness of the disfigured nails, which can discomfort, and disfigurement and may have psychosocial and emotional effects [2]. produce serious physical and occupational Onychomycosis (OM) refers to a fungal limitations. Psychosocial and emotional effects

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resulting from onychomycosis are widespread reported to be 2-13% in North America [7]. A and may have a significant impact on quality of multicenter survey in Canada showed the life [3]. Onychomycosis in patients who are prevalence of onychomycosis at 6.5% [8]. immunocompromised is associated with Studies in the United Kingdom, Spain, and increased severity and morbidity. Lesions may Finland found prevalence rates of appear atypical and require more aggressive onychomycosis to be 3-8% [4]. Onychomycosis management compared with the healthy affects persons of all races, and it affects males population. Proximal subungual (proximal more commonly than females, and is associated subungual onychomycosis) involvement is much with a family history of this infection. However, more prevalent in patients with HIV infection studies indicate that adults are 30 times more than in those without HIV infection. In this likely to have onychomycosis than children. population, white superficial onychomycosis is Onychomycosis has been reported to occur in more commonly caused by Trichophyton 2.6% of children younger than 18 years but as rubrum, rather than Trichophyton many as 90% of elderly people [4]. mentagrophytes. [4]. Diabetic patients are at The main subtypes of onychomycosis are distal increased risk of infectious complications. The lateral subungual onychomycosis (DLSO), white diabetic foot may lead to serious complications superficial onychomycosis (WSO), proximal associated with onychomycosis. Peripheral subungual onychomycosis (PSO), endonyx neuropathy and sensory loss may lead to onychomycosis (EO), and candidal increased trauma without pain in patients with onychomycosis. diabetes. Bacterial colonization and vascular Patients may have a combination of these insufficiency may exacerbate the problem and subtypes. Total dystrophic onychomycosis may lead to serious sequelae [2]. refers to the most advanced form of any Aging is the most common risk factor for subtype [4]. The pathogenesis of onychomycosis due to diminished blood onychomycosis depends on the clinical subtype. circulation, longer exposure to fungi, and nails In distal lateral subungual onychomycosis, the which grow more slowly and thicken, increasing most common form of onychomycosis, the susceptibility to infection. Onychomycosis in spreads from plantar skin and invades elderly people is complicated by diseases (eg, the nail bed via the hyponychium. Inflammation poor vision, arthritis) that prevent optimal foot occurring in these areas of the nail apparatus care. Nail changes are much more common in causes the typical physical signs of distal lateral elderly persons and often involve the fingernails subungual onychomycosis. In contrast, white and the toenails. The potential for drug-drug superficial onychomycosis is a rarer interactions is more evident and must be presentation caused by direct invasion of the addressed before initiating oral therapy [5]. surface of the nail plate. In proximal subungual Onychomycosis accounts for half of all nail onychomycosis, the least common subtype, disorders, and it is the most common nail fungi penetrate the nail matrix via the proximal disease in adults. Toenails are much more likely nail fold and colonize the deep portion of to be infected than fingernails. proximal nail plate. Endonyx onychomycosis is a Thirty percent of patients with a cutaneous variant of distal lateral subungual fungal infection also have onychomycosis. The onychomycosis in which the fungi infect the nail incidence of onychomycosis has been via the skin and directly invade the nail plate. increasing, owing to such factors as diabetes, Total dystrophic onychomycosis involves the immunosuppression, and increasing age [6]. entire nail unit [4]. People with onychomycosis The incidence of onychomycosis has been may experience significant psychosocial

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problems due to the appearance of the nail, onycholysis, in these patients Candida is only a particularly when fingers – which are always secondary colonizer. In chronic mucocutaneous visible – rather than toenails are affected [9]. , the infects the nail plate and Diagnosis of onychomycosis is generally made eventually the proximal and lateral nail folds based on its typical clinical appearance. When [4]. Other molds more commonly affect people the diagnosis is in doubt, laboratory testing older than 60 years, and their presence in the with potassium hydroxide (KOH 10%) nail reflects a slight weakening in the nail's preparation and also periodic acid Schiff testing ability to defend itself against fungal invasion of the nail is recommended [10]. [6]. On the other hand onychomycosis may occur without tinea pedis in only a couple of CAUSES scenarios: if a pedicure has inoculated the The causative pathogens of onychomycosis fungus directly into the nail, or if the patient include dermatophytes, Candida, and has used infected clippers. Older patients will nondermatophytic molds [11]. Dermatophytes often tell you that they don’t have tinea pedis, are the fungi most commonly responsible for until you ask them to take their socks off. They onychomycosis in the temperate western assume incorrectly that foot dryness is normal countries, the most common dermatophytes [13]. species are . Other dermatophytes that may be involved are T. DIAGNOSES interdigitale, Epidermophyton floccosum, T. To avoid misdiagnosis as nail psoriasis, lichen violaceum, Microsporum gypseum, T. planus, contact dermatitis, nail bed tumors such tonsurans, and T. soudanense. A common as melanoma, trauma, or yellow nail syndrome, outdated name that may still be reported by laboratory confirmation may be necessary [11]. medical laboratories is Trichophyton The three main approaches are potassium mentagrophytes for T. interdigitale. The name hydroxide smear, culture and histology [11]. T. mentagrophytes is now restricted to the This involves microscopic examination and agent of favus skin infection of the mouse; culture of nail scrapings or clippings. Recent though this fungus may be transmitted from results indicate the most sensitive diagnostic mice and their danders to humans, it generally approaches are direct smear combined with infects skin and not nails. While Candida and histological examination [14], and nail plate nondermatophytic molds particular members of biopsy using periodic acid-Schiff stain [15]. To the generation Scytalidium (name recently reliably identify nondermatophyte molds, changed to Neoscytalidium), Scopulariopsis, and several samples may be necessary [16]. , are more frequently involved in the tropics and subtropics with a hot and humid TREATMENT climate [12]. Candida spp. mainly causes Treatment of onychomycosis may consist of fingernail onychomycosis in people whose either topical or oral antifungal medications hands are often submerged in water. according to the severity of infection [17]. In Furthermore the process of nail invasion by general, topical agents should be used as Candida is not common because the yeast monotherapy only in cases involving less than needs an altered immune response as a half of the distal nail plate [10]. Although predisposing factor to be able to penetrate the topical agents improve the cure rate and nails. Despite the frequent isolation of Candida shorten the duration of treatment when used from the proximal nail fold or the subungual alongside to oral antifungal therapy, they are space of patients with chronic or rarely sufficient when used as monotherapy, as

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a result; patients treated with oral antifungal processes of advanced onychomycoses are therapy for onychomycosis report significantly time-consuming, cost-intensive, and subject to higher satisfaction and clinical improvement relatively high failure rates. Even drug courses than patients treated with topical therapy [18]. of potent systemic antimycotics, delivered In approximately half of suspected nail fungus over a period of several months, have cure cases there is actually no fungal infection, but rates of only 40 to 80% [28-30]. Recently; a only nail deformity [19]. Because of this, a new effective line for nail fungal therapy was confirmation of fungal infection should precede invented, Laser treatment, such treatment treatment [19]. Avoiding use of oral antifungal consist of four sessions with one week therapy in persons without a confirmed interval, during which all infected nails were infection is a particular concern because of the irradiated three times with laser light so that side effects of that treatment, and because the nail plate was fully covered each time[31]. persons without an infection should not have The primary aim of this treatment regime this therapy [19].Treatment of onychomycosis was to restore the nail to full health at 12 is challenging because the infection is months. The secondary aim of treatment was embedded within the nail and is difficult to to render the nail free of fungi at 3 months [31]. reach. It may take a year or more, since new The successful clinical use of lasers largely nail growth must entirely replace old, infected depends upon the wavelength, output growth [20]. The most common oral antifungals power, pulse duration ,exposure time, spot medications include terbinafine (76% effective), size, type, and color of the targeted itraconazole (60% effective) and fluconazole tissue[32-33]. One of the main advantages for (48% effective) [17]. All of these antifungals laser surgery is its bactericidal effect, in share characteristics that enhance their which laser light causes local hyperthermia, effectiveness: prompt penetration of the nail destruction of pathogenic microorganisms, and nail bed [21], persistence in the nail for and stimulation of the reparative process months after discontinuation of therapy [22]. [34]. Oral terbinafine is better tolerated than itraconazole [23], for superficial white PREVENTION onychomycosis, systemic rather than topical In order to avoid an inflamed, discomfort, and antifungal therapy is advised [24]. embarrassing toe nail, there are few simple As for Topical agents they include ciclopirox nail steps everyone should follow. Decrease our paint, amorolfine or efinaconazole [25- 26]. risk by following good hygiene practice. If an Topical treatments need to be applied daily for accidental contact with the skin of an infected prolonged periods (at least 1 year) [27]. Topical person occurs, immediately wash the area of ciclopirox results in a cure in 6% to 9% and contact with soap and warm water and dry amorolfine might be more effective [11, 27]. thoroughly with a clean towel and high heat Ciclopirox when used with terbinafine appears because fungi cannot survive laundering in high to be better than either agent alone [11]. As a temperatures [35]. result, patients treated with oral antifungal Keeping both hands and feet clean and dry, therapy for onychomycosis report significantly Clipping your fingernails and toenails short and higher satisfaction and clinical improvement keep them clean. Don't walk barefoot in areas than patients treated with topical therapy [18]. like locker rooms or public showers. Doesn't In many cases the removal of the affected part share nail clippers with other people?, Wearing of the nail during treatment appears to improve comfortable, well-fitting shoes and clean outcomes [11]. Furthermore, treatment hosiery every day, and allowing your shoes to

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Cite this article as: Alaa M. Hasan. Review on Onchomycoses: Definition, Causes, Treatment And Prevention. J

Pharm Chem Biol Sci 2015; 3(2):150-155

J Pharm Chem Biol Sci, June-August 2015; 3(2):150-155