Introduction/History of the Disease
Fungal infections are often uncomfortable conditions and they can have both physical and psychological consequences to the individual. Onychomycosis (OM) is one of the fungal diseases that results from a dermatophytic invasion of the nails. Fortunately, in the last few years, new oral treatment has successfully lowered the incidence of recurrence and side effects (Tosti & Piraccini, 1996).
What is Onychomicosis?
OM can be referred to as a localized infection of the nail, caused by a pathogenic fungi. It is characterized by discoloration and thickening of the nail, and thus, the nails are often thick, yellow, or brittle. OM can cause pain and discomfort, but it is mainly a receptacle for infection (Mooney, 1993).
OM includes a subgroup of nail infections with dermatophytic fungi known as tinea unguium. The three clinial types of tinea unguium are: distal subungual OM, proximal subungual OM, and superficial white OM (Morris, Gurevitch, & Edwards, 1992).
Distal subungual OM features thickening and opacification of the nail plate along the distal borders(Hay, 1986). In proximal subungual OM, a white spot appears beneath the proximal nail fold and may extend distally to involve the deeper layers of the nail. The surface is the initial site of invasion in superficial white OM. The surface becomes roughened and the nail plate crumbles easily, acquiring a yellow color (Arnold, Odom, & James, 1990).
Twenty percent of all nail disease can be attributed to fungi (Morris, Gurevitch, & Edwards, 1992). The main micro-organism that causes OM is a dermatophyte: Trichophyton rubrum, Trichophyton mentagrophyte, Trichophyton interdigitable, or Epidermophyton floccosum (Arnold, Odom, & James, 1990).
In addition to the nail pathogens, there are a number of nondermatophytic fungi that can cause OM; however, the end results are the same: nail plate thickening, opacification, and onycholysis (Arnold, Odom, & James, 1990). Onycholysis is the loosening of the nail plate from the nail bed (Tosti & Piraccini, 1996).
Toenails are more commonly involved in OM than finger nails; largely due to the damp conditions associated with the use of shoes. Therefore, good foot and hand hygiene is important in preventing OM. Although it is prevalent with the elderly, it may also occur in the young and healthy; and even though it might be suspected from the appearance from the nail, it can only be established with certainty by identifying the causative (Morris, Gurevitch, & Edwards, 1992).
OM affects 1-3% of the population (Tosti & Piraccini, 1996). Both men and women have indicated physical discomfort as well as a concern to the appearance. Podiatrists reported in 1997 that 54% of their patients had suffered toenail discomfort; 36% had pain while walking; and 40% had been limited to the use of the shoes.
The physician should keep close attention to the history of the patient, as well as the history of the family. Then, proper nail tissue samples should be obtained; the tissue properly identifies the invading organism, and, in turn, aids the physician in effective prescribing (Joseph, 1997).
The diagnostic evaluation can be mainly confirmed by a microscopic examination. Microscopic examinations determine OMs by heating gently thin shavings of the diseased portion of the nail in 20% potassium hydroxide. After one minute, the nail softens and then, it is placed beneath a cover slip. Dermatophyte hyphae are then easily visible (Arnold, Odom, & James, 1990).
Recurrences can be prevented by the continual use of the drugs in the previous affected nails, soles, or toe webs. Fungi can always develop again due to the poor hygiene to the area. After a successful treatment, the prognosis is that OM can either be recurrent or at a controlled state. Once the body has been infected by the fungi, it is most likely to occur again if not taken proper care of (Tosti & Piraccini, 1996).
To stop the growth of OM, treatment is required over many months. A full treatment plan should be given to the patient, in all forms, to maximize the full potential of each drug. The affected nails should be thin as possible, and oral treatment should be used to end OM. Three drugs are now widely used in the prevention and curing of OM: Fluconazole, Itraconazole, and Terbinafine (Tosti & Piraccini, 1996).
Terbinafine, a new medication, has a 50-70% chance of curing OM when administered for a 12 week period (Soignee, 1998). Fluconazole and Itraconazole in combination reduce relapses and the duration of the treatment. Fluconazole 150 mg. given once weekly or 100 mg. every other day for 3 to 6 months has been successful; in contrast, Itraconazole is effective at dosages of 200 mg. per day for 12 consecutive weeks (Tosti & Piraccini, 1996).
Many people have the idea that removal of the nail is the best way to end the fungal infection; however, what people don’t know is that when a new nail grows in the place of the old one, it usually becomes reinfected. Therefore, the best treatment is through the use of oral drugs (Soignee, 1998).
One must maintain a certain standard to prevent OM. Failure to maintain a good standard of foot hygiene, communal areas (showers or swimming pools(), and failure to dry feet througly can all cause OM (Arnold, Odom, ; James, 1990). Prevention is the cornerstone for the intervention of OM.
Arnold, H.L., Odom, R.B., ; James, W.D. (Eds.) (1990). Diseases of
skin. Philadelphia, PA: W.B. Saunders Co.
Hay, R.J. (1986). Infections affecting the nails. In P.D. Samman ;
D.A. Fenton (Eds.), The nails in disease. London: William
Heinemann Medical Books.
Joseph, W.S. (November, 1997). Special topics on onychomycosis.
[On-line]. Available: http://www.apma.org/JAPMA/vol8711.htm
Mooney, J. (1993). A review of current treatments for toenail
mycoses. Journal British Podiatric Medicine, 2, 5-6.
Morris, M.I., Gurevitch, A., ; Edwards, J.E., Jr. (1992). Fungal
infections of the skin. In S.L. Gorbach, J.G. Bartlett, ; N.R.
Blacklow (Eds.), Infectious diseases (pp. 1086-1087).
Philadelphia, PA: W.B. Sauders Co.
Physician’s desk reference (1997). Montvale, NJ: Medical Economics
Soignee, M. (1998). Onychomycosis. [On-line]. Available:
Tosti, A. & Piraccini, B.M. (1996). Diseases of the nail. In R.E.
Rakel (Ed.), Conn’s current therapy (pp. 763-764). Philadelphia
PA: W.B. Saunders Co.
Undergraduate student at the University of Texas at San Antonio