Notwithstanding the advantages of providing definitive diagnoses, the identification of fungi based on histopathological determination can be difficult and may lead to a pit of diagnoses. Therefore, the establishment of an auxiliary diagnostic method for use in routine pathological laboratories is desirable and should improve the above situation. Our previous studies have shown the superiority of in situ hybridization (ISH) for the detection of pathogenic fungi in histological specimens. This review focuses on the usefulness of ISH in the detection and identification of pathogenic fungi from formalin-fixed and paraffin-embedded (FFPE) tissue sections, and provides an overview of ISH for the diagnosis of fungal infection and retrospective autopsy analysis using molecular procedures. Based on the above, peptide nucleic acid (PNA) probes were shown to be superior in terms of the detection of target fungi and useful since histopathological diagnosis has the potential danger of being incorrect in the identification of fungi. In conclusion, we wish to emphasize that histopathological diagnosis in combination with molecular methods such as ISH and polymerase chain reaction (PCR) of FFPE samples should enhance the accuracy of identification in relation to fungi.
A 63-year-old healthy female patient presented with well defined itchy erythematous lesions on the area of her eyebrows. Her eyebrows had been tattooed two months before her visit to us. The lesions had previously been treated by application of steroid ointment and anti-histamine and steroid tablets by mouth without success. We suspected the lesions to be contact dermatitis caused by some metal element contained in the dye used for tattooing. Treatment was continued for two weeks, but the lesions spread to her cheeks and forehead. No fungal element was found from the lesions by direct microscopy at this stage. The patch-testing to 20 metal substances on her skin showed no allergic reaction. After one more week of treatment, we reexamined the scale taken from the lesions by direct microscopy, and fungal elements were found at that time. Microsporum (M.) gypseum was isolated from the scale taken from the lesions. The lesions cleared after treatment of 11 weeks' oral intake of itraconazole 100mg daily. It was found that the patient was accustomed to sleep with her dog, a Chihuahua. On examination by a veterinarian, no skin lesions were found on the dog. We speculate that the paws of the dog might have carried soil contaminated by M. gypseum, a geophilic fungus, to the area of her eyebrows which had minor trauma after being tattooed.
Background : T. tonsurans infection is spreading among combat sport athletes in Japan, and preventive measures are necessary. Methods : A questionnaire survey and hairbrush-culture tests were conducted over a 4-year period on university judo athletes from about 50 university teams affiliated with the University Judo Federation of Tokyo. Culture-positive individuals were given specific treatment recommendations based on culture results and were advised to seek treatment at a medical clinic. Culture-positive individuals were re-tested at 3 months post-treatment. Results : Approximately 65% of participants reported a history of T. tonsurans infection. The incidence of hairbrush culture-positive individuals overall gradually decreased from 11.3% (academic year 2008) to 5.4% (2011). Each year the incoming freshmen had the highest infection rate of the four academic classes. Beginning in 2009 the infection rates decreased sharply among those who had participated in the survey the previous year, and the decreases continued the following year (s) until graduation. Among culture-positive individuals, the incidence of asymptomatic carriers increased each year, from 86% in 2008 to 98% in 2011. The culture-negative conversion rate was 86% overall for those undergoing treatment. Conclusion : Preventive measures against T. tonsurans infection in the University Judo Federation of Tokyo were successful in increasing awareness of the disease, lowering the incidence of infection, and detecting asymptomatic carriers who require treatment.