Dermatophyte onychomycosis

Dermatophyte onychomycosis is a frequently occurring condition which may be isolated or associated with tinea pedis and/or tinea manuum. The role of occupational activities is therefore similar to that in tinea pedis. It affects one or more toenails it is less common on the hands. The infection begins at the distal extremity of the nail bed or nail fold. Onychomycosis may have different clinical characteristics in some cases, leukonychia affecting part of the distal nail extremity but also extending along a nail fold towards the cuticle is the major symptom. Full thickness, including the superficial plate, accounts for the pearly mat appearance of the infected area. In other cases, massive destruction of the nail does occur, spicules of which are detached all along the free border (Fig. 11). 

Recently, the treatment of dermatophyte onychomycosis has been studied extensively. The schedules proposed are as follows terbinafine 250 mg/day for 3-4 months according to the severity of the disease and the response to the treatment (Goodfield et al. 1989). Itraconazole is more efficient when a pulse therapy is conducted as follows 100 mg four times per day for 1 week followed by 3 weeks of no treatment. Three or four consecutive waves are prescribed following the same schedule (Degreef et al. 1987). 

Candida paronychia is often difficult to treat. Topical treatment is insufficient the best therapeutic approach is intermittent (pulsed) itraconazole or fluconazole, following the schedules indicated in the treatment of dermatophyte onychomycosis. Prevention of candidosis is straightforward. It includes the avoidance of maceration at work. Chronic paronychia is best prevented by the use of appropriate gloves. The avoidance of contact with foods incriminated in the initiating protein contact dermatitis (assessed by positive prick tests) is mandatory. 

The purpose of the present study was to compare two treatment modalities to obtain diseased nail chemical avulsion in toenail onychomycosis. This was a multicentre, randomised, parallel-group, open-label, active controlled study. Male or female adult patients with distal-lateral or lateral subimgual dermatophyte onychomycosis on at least 12.5% of the great toenail were randomised either to a 40% urea ointment with plastic dressing group (n=53) or to a bifonazole urea ointment group (n = 52) [22 ]. 

Onychomycosis (capsules only) Treatment of onychomycosis of the toenail with or without fingernail involvement and onychomycosis of the fingernail because of dermatophytes Tinea unguium) in nonimmunocompromised patients. Oropharyngeal/esophageal candidiasis (oral solution only) Treatment of oropharyngeal or esophageal candidiasis. 

Despite negligible cerebrospinal fluid concentrations, itraconazole shows promise in the treatment of cryptococcal and coccidioidal meningitis. Additional uses for itraconazole include treatment of vaginal candidiasis, tinea versicolor, dermatophyte infections, and onychomycosis. Fungal naU infections account for most use of this drug in the outpatient setting. 

In the treatment of ringworm of the beard, scalp, and other skin surfaces, 4 to 6 weeks of therapy is often required. Therapy failure may be to the result of an incorrect diagnosis superficial candidiasis, which may resemble a dermatophyte infection, does not respond to griseofulvin treatment. Onychomycosis responds very slowly to griseofulvin (1 year or more of treatment is commonly required) and cure rates are poor itraconazole and terbinafine hydrochloride are more effective than griseofulvin for onychomycosis. 

Fluconazole is well absorbed following oral administration, with a plasma half-life of 30 hours. In view of this long half-life, daily doses of 100 mg are sufficient to treat mucocutaneous candidiasis alternate-day doses are sufficient for dermatophyte infections. The plasma half-life of itraconazole is similar to that of fluconazole, and detectable therapeutic concentrations remain in the stratum corneum for up to 28 days following termination of therapy. Itraconazole is effective for the treatment of onychomycosis in a dosage of 200 mg daily taken with food to ensure maximum absorption for 3 consecutive months. Recent reports of heart failure in patients receiving itraconazole for onychomycosis have resulted in recommendations that it not be given for treatment of onychomycosis in patients with ventricular dysfunction. 

Fig. 4. Onychomycosis. Another typical manifestation of dermatophyte infection, starting from the distal border of the nail. 

De Backer M, De Vroey C, Lesaffre E. Scheys I, De Keyser P. Twelve weeks of continuous oral therapy for toenail onychomycosis caused by dermatophytes a doubleblind comparative trial of terbinafine 250 mg/day versus itraconazole 200 mg/day. J Am Acad Dermatol 1998 38(5 Pt 3) S57-63. 

Onychomycosis is infection of the nails of the fingers or toes caused by dermatophytes (fungi that live on the outer keratinous layer of the skin), yeasts or moulds. 

Onychomycosis Fungal infection of the nails is caused most frequently by dermatophytes and Candida. Mixed infections are common. The nail must be cultured or chpped for histological examination before initiating therapy because up to a third of dystrophic nails that appear clinically to be onychomycosis are actually due to psoriasis or other conditions. 

A) Its activity is restricted to dermatophytes It is effective in onychomycosis It inhibits squalene epoxidase It is only used topically Rifampin may increase its clearance... 

Ciclopirox is a hydroxylated pyridinone that is employed for superficial dermatophytic infections, principally onychomycosis. Ciclopirox has a unique mechanism of action through chelation of polyvalent cations, such as Fe ", which causes inhibition of a number of metal-dependent enzymes within the fungal cell. Although ciclopirox has been available for more than 30 years, a new formulation of an 8% lacquer has been recently introduced for treating nail infections (55). 

The most common form of tinea pedis is located in the toe webs. The fourth interdigital web is preferentially infected, but the other webs can also be infected, on one or both feet. The clinical symptoms are characterised by a whitish, diffuse maceration in the cleft marginated by a collarette of continuous desquamation (Fig. 10). In some cases, there is a small, painful fissure running along the line of the cleft. The entire area is ulcerative and macerated from microbial superinfection. Itching is usually present. In T. rubrum infections, a squamous, hyperkeratotic variety that is particularly chronic and resistant to treatment and that affects the soles, heels and sides of the feet ( moccasin foot ), is often found (Hay and Moore 1998). The dorsal surfaces of the toes and feet are not often affected, but associated onychomycosis is common. Tinea pedis is sometimes associated with reactive plantar pompholyx extremely pruritic, coalescent vesicular eczema is observed. Microscopic examination sometimes reveals the presence of dermatophytic filaments in these so-called id reactions. 

Goodfield MJD, Rowell NR, Forster RA, Evans EG, Raven A (1989) Treatment of dermatophyte infection of the finger- and toenails with terbinafine in onychomycosis. Br J Dermatol... 

---