Dermoscopic features in 12 cats with dermatophytosis and in 12 cats with self‐induced alopecia due to other causes: an observational descriptive study

Abstract

Background -Dermoscopy is a non invasive technique allowing rapid and magnified in vivo observation of the skin and structures that lie beneath the skin surface. Various congenital and acquired hair shaft abnormalities may be also evaluated by dermoscopy and characteristic features of Microsporum canis-induced tinea capitis and trichotillomania in people have also been reported. Objectives -To describe the dermoscopic findings observed in cats with patchy alopecia due to Microsporum canis infection and in cats with self-inflicted hair loss. Animals -Twenty-four client-owned cats presented to a private veterinary referral practice. Methods -Dermoscopy was performed with both an handheld non-polarized light dermoscope at 10-fold magnification and a videodermoscope at 40-fold magnification. Results -At 10-fold magnification, the most characteristic findings observed in circumscribed lesions of cats with dermatophytosis were opaque, broken hairs slightly curved with an homogeneous thickness (comma-like structures) and a variable amount of brown-to-yellow greasy scales. In cats with self-induced alopecia, multiple hairs with a normal shaft suddenly and cleanly broken at different lengths, short tufts of hairs broken at equal level , hook-like and coiled hairs were observed. By videodermoscopy, hair shaft thickness was also measured. Conclusions -This observational descriptive study suggests that dermoscopy may represent an in vivo non-invasive technique helpful in differential diagnosis of patchy alopecia in cats.

Evaluation of dermoscopy in the diagnosis of naturally occurring dermatophytosis in cats

“…Both comma and corkscrew hairs have been documented in people with tinea capitis due to dermatophytes of the genera Trichophyton and Microsporum (Figure ) . A previous study described the dermoscopic features between cats with dermatophytosis and cats with self‐induced alopecia due to other causes . “Comma‐like” hairs are not found on healthy cats …”

“…A previous study described the dermoscopic features between cats with dermatophytosis and cats with self‐induced alopecia due to other causes . “Comma‐like” hairs are not found on healthy cats …”

Alopecia Areata in a Dog: Clinical, Dermoscopic and Histological Features

“…Comma-like hairs have been described as the main characteristic features both in cats and dogs with dermatophytosis [11,12,13]. Canine pattern alopecia has been evaluated by dermoscopy in 20 short-haired dogs [14] and hair shaft thinning, scattered circle hairs, plugging of the follicular infundibulum with a yellow-brown material and honeycomb-like pattern pigmentation in sun-exposed areas were reported as the prevalent features.…”

Dermatophytosis in cats and dogs: a practical guide to diagnosis and treatment

“…Its primary use is to find abnormal hairs for direct examination and/or culture. Infected hairs are opaque, slightly curved or broken and have a homogenous thickness (Fig 5) (Scarampella and others 2015, 2017). …”