BACKGROUND: Trichophyton (T.) erinacei is a rare but emerging zoonotic dermatophyte that is rarely isolated as a human pathogen, with only a few cases extensively described in the literature.
METHODS: We conducted a systematic search to identify eligible articles reporting demographics, clinical characteristics, and the therapeutic approach regarding T. erinacei infection in humans.
RESULTS: 168 patients affected by T. erinacei were reported in the international literature between inception and November 2023. Only 56 cases (32.1%) were fully described. The median age at diagnosis was 26 years, the female/male ratio was around 2:1. The main source of the disease was the hedgehog. The infection presented with a combination of erythema, scaly plaques, pustules, papules, vesicles, oedema, and erosion; the most common locations were the hands and the head. The most frequently conducted examination was fungal culture, but gene sequencing and mass spectrometry improved both speed and precision in the most recent diagnostic course. Topical clotrimazole and systemic terbinafine were the most chosen treatment.
CONCLUSIONS: Trichophyton erinacei should be considered in patients with erythematous scaly patches and recent contact with hedgehogs. Terbinafine should be considered as a first-line effective treatment, griseofulvin and azoles could be considered valid alternatives.

Fleas are ectoparasites of various animals, including Homo sapiens Linnaeus, 1758 (Primates: Hominidae). Among the species relevant to the human health field, either due to their dermatopathological potential or because of their role as vectors of microorganisms responsible for infectious diseases, such as plague or murine typhus, are the human flea, oriental rat flea, closely related cat and dog fleas, and chigoe flea. However, other species can accidentally infest humans. We have herein reported two unusual cases of humans infested and bitten by Archaeopsylla erinacei, the hedgehog flea. This species has been identified using stereomicroscopy, on the base of key characteristics. Furthermore, a brief literature review has revealed that hedgehog fleas could carry human-infectious agents, such as Rickettsia felis Bouyer et al. 2001 (Rickettsiales: Rickettsiaceae) or Bartonella henselae Regnery et al.1992 (Rhizobiales: Bartonellaceae). Using molecular biology, we thus tested nine A. erinacei specimens taken from these patients, for several bacteria species commonly associated with hematophagous arthropods, implicated in human pathology. However, all our samples were proven negative. The role of A. erinacei in human epidemiology has never been evaluated to date. This report sought to remind us that these fleas can be accidental parasites in humans. In addition, recent findings pertaining to bacteria of medical interest that are present in these insects should be brought to the fore, given that the question of their role as vectors in human infections remains unanswered and deserves further investigation.

Rhabdomyosarcoma (RMS) histologically resembles developing skeletal muscle and is thought to solely originate from a differentiation block in muscle progenitors. We demonstrate that RMS can arise from endothelial progenitor cells following reprogramming and myogenic transdifferentiation. These results highlight how tumors with identical morphological features can arise from different cell types and offer insight into RMS formation in non-myogenic tissue.