Shyam Bhanushankar Verma

Background: Trichophyton indotineae has emerged as a significant novel species causing tinea corporis/cruris/faciei, with established endemicity in a few regions and potential for expanding endemic zones in future. Objectives: We aimed to develop consensus on disease definitions, diagnosis and treatment of T. indotineae infection. Methods: Relevant literature from 2017 onwards was analysed and presented to the panel of dermatology experts, followed by circulation of a structured Google questionnaire encompassing various aspects of systemic and topical treatment, including special scenarios. Repeat rounds with modified questions were conducted in domains where (75%) consensus was not achieved, till a maximum of three rounds. Disease definitions were arrived at by discussion among clinical experts. Mycological (diagnostic) guidelines were formulated by the expert mycology members through peer review of each other's drafts. Results: The panel comprised 14 dermatologists, 2 mycologists and 1 pharmacologist. Disease definitions for clinical and research use are presented. KOH smear testing is recommended in clinically doubtful cases, whereas culture, antifungal susceptibility testing and sequencing are recommended for monitoring trends of prevalent species and drug susceptibility in specialized mycology laboratories. A total of 87 therapeutic questions were put to the 14 dermatologists. Key therapeutic recommendations include the use of itraconazole (ITZ) as a first‐line systemic agent and terbinafine (TRB) (higher dose) as a second line, switching systemic antifungal in case of inadequate response at 4 weeks, use of prolonged treatment (till cure) and treatment of relapses with the same regimen as used for initial treatment. Recommendations for treatment monitoring and treatment in special scenarios such as paediatric patients, pregnancy, lactation, renal or hepatic dysfunction, cardiac failure and patients on topical/systemic steroids or immunosuppressives are presented. Conclusions: The panel has made recommendations on clinical and diagnostic aspects of T. indotineae infections, which would improve patient outcomes and foster academic communication and research.

Mycosis fungoides is a misnomer that means ‘mushroom‐like fungal disease’, but it is, in fact, the most common form of cutaneous T‐cell lymphoma. The diagnosis of mycosis fungoides is often delayed due to non‐specific symptoms and cutaneous signs that mimic other common benign inflammatory dermatoses. We report a case series to emphasize the importance of considering fungal skin infections in patients with mycosis fungoides, especially when the rash is atypical.

Background and Objective: Trichophyton indotineae is a globally emerging, frequently antifungal‐resistant fungus causing severe dermatophytosis. To inform prevention efforts, we analysed the genomic epidemiology and resistance to terbinafine (first‐line oral antifungal) from a collection of multinational T. indotineae isolates collected from patients with clinically suspected dermatophytosis during 2016–2023.Methods: We performed whole genome sequencing and phylogenetic tree analysis based on single‐nucleotide polymorphisms (SNPs). T. indotineae phylogenetic results were correlated with patient demographic characteristics and isolate terbinafine susceptibility profiles that were determined by antifungal susceptibility testing and squalene epoxidase gene sequencing. Trichophyton mentagrophytes and Trichophyton interdigitale isolates from the USA, and Trichophyton rubrum isolates from three countries were added for contextual analysis.Results: Among 347 T. indotineae isolates, 227 (65%) were in vitro resistant to terbinafine. Countries represented were India (43%); Germany (21%); Bangladesh (8%); United States (8%); United Arab Emirates (7%); Iraq (5%); Finland (3%); Poland (2%); Austria, Canada, Cambodia, Estonia, Singapore, and Switzerland (each < 1%). Median SNP difference between isolates was 106 SNPs (range: 0–392). Clustering by age, sex, or country was not observed. One subcluster was composed of terbinafine‐resistant isolates with a specific squalene epoxidase gene mutation (F397L) and was widely dispersed among 10 countries. Intra‐species genomic diversity was greater among 19 T. rubrum isolates (260 SNPs [range: 73–1038]), or among 10 T. mentagrophytes/T. interdigitale isolates from the USA compared with the intra‐species diversity of the T. indotineae isolates.Conclusions: Our findings corroborate T. indotineae's recent emergence and ongoing international transmission and suggest the rapid spread of a subset of terbinafine‐resistant isolates. Continued efforts are necessary to mitigate this pathogen's spread.

Trichophyton (T.) mentagrophytes ITS genotype VIII, also known as Trichophyton indotineae, is a new species of the T. mentagrophytes/T. interdigitale complex and its first records, albeit under a different species name, are from the Indian subcontinent, Middle Eastern Asia, and West Asia. T. mentagrophytes genotype VIII (T. indotineae) has spread globally and has now been documented in over 30 countries. The aim of this study was to investigate the occurrence and proportion of terbinafine- and itraconazole-resistant isolates of T. mentagrophytes ITS genotype VIII (T. indotineae) in Bangladesh. This was part of an official collaborative project between IADVL (Indian Association of Dermatologists, Venereologists, and Leprologists) and Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh. Over a period of 6 months, ninety-nine patients of chronic recalcitrant tinea corporis were recruited from BSMMU hospital. Species identification was performed by fungal culture and morphological observation of the upper and lower surfaces of fungal colonies, as well as by using fluorescent microscopy. In addition, a PCR (polymerase chain reaction)-ELISA was performed to group the patients into those with the T. mentagrophytes/T. interdigitale complex. The internal transcribed spacer (ITS) gene was sequenced. Samples were tested for resistance to terbinafine and itraconazole by mutational analyses of the squalene epoxidase (SQLE) and the ergosterol 11B (ERG11B) genes. A total of 79/99 samples showed a positive culture. In 76 of these isolates, T. mentagrophytes ITS genotype VIII (T. indotineae) could be reliably identified both by culture and molecular testing. Resistance testing revealed terbinafine resistance in 49 and itraconazole resistance in 21 patients. Among these, 11 patients were resistant to both the antifungal agents. Mutations L393S, L393F, F397L, and F397I of the SQLE gene were associated with terbinafine resistance. Resistance to itraconazole could not be explained by mutations in the ERG11B gene. Infections with T. mentagrophytes ITS genotype VIII (T. indotineae) have become a public health issue with potentially global ramifications. About 62% of samples from Bangladesh showed resistance to terbinafine, making oral itraconazole the most effective drug currently available, although resistance to itraconazole and both terbinafine and itraconazole also exists.

Post herpetic itch (PHI) is a less commonly reported sequela of herpes zoster. It can begin upon the resolution of the lesions or several weeks later. PHI is neuropathic in nature and is said to be caused by neural injury in the form of demyelination of itch-transmitting nerve fibers in the skin. The majority of PHI resolves over weeks to months with symptomatic treatment. We report a case of PHI resulting in frictional alopecia of eyebrows and scalp due to frequent rubbing of the skin and hairs secondary to bothersome neuropathic itch.