Case Reports. Six cases of infection due to Trichophyton verrucosum

A Rare Case of Cutaneous Trichophyton verrucosum of the Forearm in a 51-Year-Old Cattle Farmer

Trichophyton verrucosum is a pathogen causing superficial mycoses in cattle worldwide and is one of the few zoophilic dermatophytes. Farmers and veterinarians are at a higher risk for infection owing to frequent direct animal contact. An increase in cases among humans has been observed in the past few years. We report a rare case of T verrucosum of the forearm in a 51-year-old cattle farmer, who after initial treatment with antibiotics and surgery, and in whom diagnosis was delayed, was finally successfully treated with terbinafine and itraconazole.

Berufliche Infektion mit Trichophyton verrucosum bei einem Rinderzüchter

Die Kälberflechte ist eine durch Tiere übertragene Pilzinfektion, die berufsbedingt auftreten und nach Nr. 3102 BKV (Berufskrankheiten-Verordnung) als Berufskrankheit anerkannt werden kann. Die durch Trichophyton verrucosum ausgelöste Zoonose zeichnet sich häufig durch einen schweren klinischen Verlauf aus, der nicht selten als bakterielle Infektion fehlgedeutet und primär antibiotisch behandelt wird. Die Gewinnung und mykologische Untersuchung von Schuppenmaterial ist diagnostisch entscheidend; auch eine Biopsie kann wegweisend sein. Die orale Therapie erfolgt leitliniengemäß mit Terbinafin. Zudem ist zum Schutz vor Reinfektionen auf besondere Hygienemaßnahmen in Ställen zu achten.

Extensive tinea capitis and corporis in a child caused by Trichophyton verrucosum

A 3-year-old boy presented with multiple lesions of tinea corporis with dermatophytids, and subsequent inflammatory lesions with alopecia on the scalp. At the beginning, topical clobetasone butyrate was prescribed. The infection was diagnosed as dermatophytosis on the basis of positive direct microscopy and fungal culture. The etiological agent was isolated from all sampled sites and identified as Trichophyton verrucosum. Clonal nature of the infection was confirmed by random amplified polymorphic DNA (RAPD) analysis. The child lived in close vicinity of cattle. He was successfully treated with itraconazole.

Cognitive and visual diagnostic errors in dermatology: part 1

Sir William Osler famously, and ironically, stated that 'Medicine is a science of uncertainty and an art of probability'. The processes by which each physician metes out diagnostic uncertainty and navigates probabilities in dermatology is far from uniform. While certain ubiquitous cognitive and visual heuristics can enhance diagnostic speed, they also create pitfalls and thinking traps that introduce significant variation in the diagnostic process. Discussed in this part of a two-part article are various cognitive and visual heuristics as they pertain to skin disease, with an introduction and special attention paid to the heuristic methods classically applied by dermatologists. How to best address error and improve our thought processes will be addressed in part 2.

Emerging moulds: epidemiological trends and antifungal resistance

Invasive fungal infections (IFIs) are associated with high morbidity and mortality in immunocompromised patients. Although Aspergillus spp. remain an important cause of IFI, other moulds such as Fusarium spp., dematiaceous fungi and Mucorales have become increasingly prevalent among this patient population. Diagnosis and treatment of invasive mould infections remain a challenge. Because of the poor prognosis associated with IFIs, understanding the activity, efficacy and limitations of the available drugs is critical to select the appropriate antifungal agent on an individualised basis.

High infection rate of Trichophyton verrucosum in calves from Central Italy

Recent epidemiological features of the zoonotic dermatophyte Trichophyton verrucosum were investigated in 294 calves from 20 farms located in Central Italy. By the combination of microscopic examinations and fungal cultures, the total prevalence rate of T. verrucosum infection was found to be high, with 87.7% of samples yielding positive results and 100% of farms being infected. Farm to farm prevalence of infection varied from 25% to 100% of the examined calves. Prevalence rates were higher in females than males (91.6% versus 84%), in >3-< or =6 than >6-< or =9 month old calves (89.8% versus 85.7%), in purebred than in crossbred (88.5% versus 81.8%), and in symptomatic than asymptomatic ones (95.7% versus 80.4%). T. verrucosum was as prevalent in semi-intensive as in intensive breeding system (88.2% versus 87.6%) but more prevalent in calves raised for meat rather than milk production (91.1% versus 84.9%), and reared under conventional than organic production management system (89.3% versus 82.6%). Prevalence rates were also higher when the cattle present in the farm were of mixed origin, rather than when the whole stock was purchased or was born in the farm (92% versus 88.2% and 85.7%), when other cattle in the farm were showing skin signs (90% versus 84.2%), and at least one case of human ringworm was recorded in the farm (90.9% versus 86.1%). No statistically significant association was found. Therefore, T. verrucosum infection may be more widespread in calves from Central Italy than it was previously thought to be. Calves of any sex, breed, age, and of any of the farm condition considered, are highly exposed to the risk of infection. As calves may play a considerable role as reservoirs of the infection, our results highlight the need to determine the incidence and the importance of T. verrucosum ringworm in personnel involved with cattle care in Italy and elsewhere.

Perniosis-like tinea corporis caused by Trichophyton verrucosum in cold-exposed individuals

Trichophyton verrucosum is a zoophilic infectious agent causing 98% of the dermatophytic infections of cattle. Transmission to humans has, until recently, been rare. One reason for an increase of infection in humans and animals seems to be the decrease in immunisation of cattle. We report on three cases of pertinent human infections with disseminated, sharply defined, bluish red, partly oedematous nodules and plaques in particular not only on the thighs, but also on the trunk and arms. Two of our patients work with farm animals. The third one works as an assistant in a butcher shop, but lives on a cow farm. All three patients are often exposed to the cold. In all three cases T. verrucosum was detected by culture. Tinea corporis was histologically confirmed in two patients. Based on the microbiological results, we began a combined systemic and local antimycotic therapy with fluconazole 50 mg day(-1) in two patients, itraconazole 100 mg day(-1) in one patient p.o. combined with topical ciclopiroxolamine. All patients were cured. Dermatophytosis caused by T. verrucosum can, under certain circumstances, such as frequent exposure to cold or a long-term corticosteroid therapy, mimic the characteristic clinical picture of perniosis, as we demonstrate here.

Outbreak of Trichophyton verrucosum in China Transmitted from Cows to Humans

Twenty percent of 1000 dairy cows were infected with Trichophyton verrucosum in a newly established dairy farm in western China. The disease was transmitted to 30 of 100 animal workers. The source of the outbreak is unknown but it is suspected that naïve cattle which were transported from Holland to China became infected after they arrived in Xinjiang province (West China) where the fungus is endemic in nature, prepuberty school children and various livestock.