Onychomycosis caused by Microsporum canis: treatment with itraconazole

Fingernail onychomycosis caused by Microsporum canis in a teenager

A healthy 15-year-old girl presented with a total dystrophic nail plate and subungual hyperkeratosis over her left 3rd fingernail. Her 2-year-old shorthair cat had circular erythematous patches of alopecia on the left aspect of its forehead. Fungal culture from the affected nail and her cat both grew Microsporum canis. The girl was treated with terbinafine with clinical and mycological cure.

Rapid detection of dermatophytes and Candida albicans in onychomycosis specimens by an oligonucleotide array

Background

Onychomycosis is a fungal infection of nails, leading to the gradual destruction of the nail plate. Treatment of onychomycosis may need long-time oral antifungal therapy that can have potential side effects, thus accurate diagnosis of the disease before treatment is important. Culture for diagnosis of onychomycosis is time-consuming and has high false-negative rates. To expedite the diagnosis, an oligonucleotide array, based on hybridization between immobilized oligonucleotide probes and PCR products, for direct detection of dermatophytes and Candida albicans in clinical specimens was evaluated.

Methods

Species-specific oligonucleotide probes designed from the internal transcribed spacer (ITS) regions of the rRNA gene were immobilized on a nylon membrane. The assay procedures consisted of PCR amplification of the ITS using universal primers, followed by hybridization of the digoxigenin-labeled amplicons to probes on the array. Thirty two nail samples (29 patients) were analyzed by the array, and the results were compared with those obtained by culture. Array-positive but culture-negative samples were confirmed by cloning and re-sequencing of the amplified ITS and by reviewing patient’s clinical data. The total recovery of culture and confirmed array-positive but culture-negative results was considered 100% and was used for performance evaluation of both methods.

Results

Concordant results were obtained in 21 samples (10 positives and 11 negatives) by both methods. Eleven samples were array-positive but culture-negative; among them, 9 samples were considered true positives after discrepant analysis. Comparing with culture, the array had significantly higher sensitivity [100% (95% CI 82.2% −100%) vs 52.6% (28.9% −75.5%), p <0.001] and negative predictive value [100% (71.3% −100%) vs 59.1% (36.4% −79.3%), p <0.05), while no significant differences were observed in specificity (84.6% vs 100%, p =0.48) and positive predictive value (90.5% vs 100%, p =1.0). The whole procedures of the array were about 24 h, whilst results from culture take 1 to 3 weeks.

Conclusions

The array offers an accurate and rapid alternative to culture. Rapid diagnosis can expedite appropriate antifungal treatment of onychomycosis. However, the single site nature of this study conducted at a referral hospital invites caution.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0581-5) contains supplementary material, which is available to authorized users.

Pharmacoeconomic analysis of ciclopirox nail lacquer solution 8% and the new oral antifungal agents used to treat dermatophyte toe onychomycosis in the United States

BACKGROUND

Recently a novel topical nail lacquer, ciclopirox solution 8%, has been approved for the treatment of onychomycosis.

OBJECTIVE

This was undertaken to determine the most cost-effective treatment for the treatment of dermatophyte onychomycosis of the toes in the United States in 2000.

METHODS

The nature of the problem was defined. The drug comparators were ciclopirox nail lacquer, terbinafine, itraconazole (pulse), itraconazole (continuous), fluconazole, and griseofulvin. A decision analytic model that reflected the manner in which pedal tinea unguium is managed was produced. Studies that have evaluated the efficacy of the nail lacquer and the oral antifungal agents for this indication were identified. Appropriate studies were used in a meta-analysis to determine the mycologic and clinical response rates when the drug comparators are used for the treatment for toe dermatophyte onychomycosis. For each drug comparator a cost of regimen analysis was carried out. This is the sum of the drug acquisition cost, the cost of medical management, and the cost of managing adverse effects. Next, the expected cost of management was calculated, disease free days were determined, and a sensitivity analysis was conducted.

RESULTS

For each comparator the meta-analytic average mycologic cure (MC) rate and clinical response (CR) rates were: ciclopirox nail lacquer (MC: 52.6 +/- 4.2%, CR: 52.4 +/- 9.0%), griseofulvin (MC: 41.1 +/- 20.4%, CR: 33.7 +/- 14.1%), itraconazole (continuous) (MC: 66.3 +/- 4.2%, CR: 70.3 +/- 4.2%), itraconazole (pulse) (MC: 70.8 +/- 5.7%, CR: 73.6 +/- 4.6%), terbinafine (MC: 77.2 +/- 4.0%, CR: 75.3 +/- 2.9%), and fluconazole (MC: 65.6 +/- 7.1%, CR: 66.5 +/- 11.7%). The cost of regimen for the drug comparators was: ciclopirox nail lacquer $325.2, griseofulvin $1413.1, itraconazole (continuous) $1410.2, itraconazole (pulse) $811.7, terbinafine $890.1, and fluconazole $966.8. The cost/mycologic cure rate and expected cost/expected symptom free day were, ciclopirox nail lacquer ($618.2, 1.69), griseofulvin $3438.2, 5.3), itraconazole (continuous) ($2126.9, 3.52), itraconazole (pulse) ($1146.4, 2.01), terbinafine ($1153.0, 2.14), and fluconazole ($1473.7, 2.10). The relative cost-effectiveness was ciclopirox nail lacquer 1.00, itraconazole (pulse) 1.19, fluconazole 1.24, terbinafine 1.27, itraconazole (continuous) 2.08, and griseofulvin 3.13. Sensitivity analysis indicated that ciclopirox nail lacquer was a cost effective alternative compared with the oral regimens of terbinafine, itraconazole (continuous), and griseofulvin when clinical response rate was used as the primary efficacy parameter.

CONCLUSION

Ciclopirox nail lacquer solution 8% is a recent addition to the armamentarium of therapies available to the physician and patient for the treatment of onychomycosis. The nail lacquer is a cost effective agent compared with the oral antifungal therapies, terbinafine, itraconazole, fluconazole, and griseofulvin.

Study of onychomycosis in Córdoba, Spain: prevailing fungi and pattern of infection

From a total of 20,004 patients seen during two years, we carried out a mycologic nail investigation (direct microscopy and repeated cultures). Ninety-three (43.2%) of the nails were judged to be infected by their clinical appearance. They fulfilled the laboratory criteria required to start antifungal treatment (isolation of the same fungus in culture on two consecutive occasions), but only in 64 cases (29.7%) was there a clinical and mycological recovery once antifungal treatment and follow up were completed. yeasts were isolated in two thirds of the cases of onychomycosis, mainly from fingernails. Candida albicans, C. parapsilosis or both were the most prevalent species. Dermatophytes were found in 18.8% of the samples, especially from toenails. Trichophyton rubrum was the predominant species. Non-dermatophytic filamentous fungi were cultured in 17.2%, Scopulariopsis brevicaulis being the most prevalent species. The highest prevalence of onychomycosis was found in patients between 50 and 70 years of age. Females were affected more frequently than males. Fingernails were affected more frequently than toenails. Proximal subungual onychomycosis, secondary to paronychia (PSOp), was the most prevalent clinical type, although primary distal and lateral subungual onychomycosis (DLSO) and total dystrophic onychomycosis (TDO) were also frequent. PSOp was only observed in fingernails, while DLSO was almost only seen in toenails and TDO in both fingernails and toenails. All the clinical types were more frequent in women except TDO, which showed a similar prevalence in both sexes.

Unusual Microsporum canis infections in adult HIV patients

Tinea capitis in men, even if infected with HIV, is infrequent. Microsporum species nail infections are extremely rare. In most cases Microsporum canis infection is usually easy to treat with antifungal agents. We describe two HIV-infected men with an unusual M. canis infection. Both patients had tinea capitis, presenting as alopecia in one and scaling of the scalp in the other. One patient also had tinea unguium caused by M. canis. Ketoconazole was ineffective in both patients; terbinafine was tried in one patient without benefit; itraconazole was effective in both, but treatment took many months and only one patient was cured.