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

Dermoscopic features of benign sebaceous proliferations in dogs: Description, assessment and inter-observer agreement

BACKGROUND

Dermoscopy is a useful, noninvasive technique also used to assess sebaceous lesions in humans. Sebaceous hyperplasia, sebaceous adenoma and sebaceous epithelioma are common cutaneous lesions in dogs; however, their dermoscopic features have not been investigated.

HYPOTHESIS/OBJECTIVES

The objectives of this study are to describe the dermoscopic features of canine sebaceous lesions and to assess the interobserver agreement on dermoscopic parameters.

ANIMALS

Thirty-four lesions excised from 17 client-owned dogs, histologically confirmed as sebaceous proliferations, were included in this study.

MATERIALS AND METHODS

Sebaceous lesions were evaluated in vivo at ×10 magnification with a handheld dermoscope. Each dermoscopic image was assessed independently by two ECVD board-certified veterinary referral clinicians and an ECVD resident.

RESULTS

Thirty sebaceous hyperplasias, two sebaceous adenomas and two sebaceous epitheliomas were included. Dermoscopically, most lesions (91%) had single or multiple, well-defined, white-yellowish structures composed of grouped ovoid areas (clods). Irregular linear and, less commonly, arborising vessels were detected at the periphery of the yellow lobular-like structures in 93% of sebaceous hyperplasias and in 50% of neoplastic lesions. Erosions were seen in 6% of sebaceous hyperplasias and 50% of neoplastic lesions. Good interobserver agreement was found for white/yellowish clods (k = 0.75), yellow scales (k = 0.83), brown/grey dots (k = 0.80), erosions (k = 0.82) and red/brownish scales/crusts (k = 0.75). There was moderate agreement for fissures (k = 0.48) and vascular pattern (k = 0.51-0.53).

CONCLUSIONS AND CLINICAL RELEVANCE

Dermoscopy represents a useful technique to assess sebaceous gland proliferations in dogs, as it is in humans.

Clinical techniques in veterinary dermatology: Dermoscopy

Dermoscopy is a noninvasive, painless, easy-to-perform technique used in human and veterinary medicine for rapid and magnified in vivo observation of dermatological lesions and disease. Dermoscopy can lead to a swifter diagnosis and may eliminate the need to perform more invasive diagnostic testing such as skin biopsies. To perform dermoscopy, the clinician needs a dermoscope and a software program equipped with image capture for pattern identification. Two techniques exist for dermoscopy: standard contact, where the dermoscope is applied directly to the patient's skin with the use of a liquid interface, or noncontact, where there is no direct contact between the skin and the dermoscope. The most important criteria to be considered when using dermoscopy are the morphology/arrangement of vascular structures, scaling patterns, colours, follicular abnormalities and specific disease features. Application of dermoscopic findings should always be correlated with the patient's history, clinical signs and the morphology of the skin lesions. Dermoscopy does require an initial financial and time investment by the clinician, yet this technique can quickly and easily help to identify patterns of disease that correlate with clinical diagnosis of dermatological disease.

Bovine ringworm - Detection of Trichophyton verrucosum by SYBR-Green real-time PCR

Trichophyton verrucosum is the most commonly dermatophyte involved in cattle ringworm. This work reported a case of bovine dermatophytosis due to Trichophyton verrucosum detected from the clinical sample by SYBR-Green real-time PCR. The strategy was based on the DNA extraction directly from the infected hair followed by real-time PCR and melting-point analysis. A faster and differential diagnosis was observed when compared to the conventional mycological methodology for detection and identification of Trichophyton verrucosum.

Videodermoscopic examination of the skin and its products in purebred Arabian horses in the summer season

Videodermoscopy is a method that enables the examination of many parameters of the skin and its structures. The aim of this study was to assess specific dermoscopic parameters in purebred Arabian horses during the summer. The study involved 21 clinically healthy purebred Arabian horses (18 mares and three stallions) that had not been used for breeding and were 1 to 25 years old. The videoderoscopic evaluation was performed on seven selected areas of the body: forehead, mane, neck, chest, flank, rump, and tail. The tests were carried out with Vidix and Olympus cellSens specialised software. Videodermoscopy revealed that the skin was pigmented in all of the bay horses, in one of the seal brown horses, and in the 10 grey horses. Only one grey horse and one chestnut horse had unpigmented skin. Hair thickness ranged from 44.82 µm (neck) to 75 µm (mane). Regarding the amount of hair in the field of view, the highest and lowest numbers of hairs were found on the neck (3,004) and mane (990), respectively. A valuable insight obtained from our research is that it is possible to use digital image analysis for precise quantitative and qualitative evaluations of the skin and its structures.

Current Topics in Dermatophyte Classification and Clinical Diagnosis

Dermatophytes are highly infectious fungi that cause superficial infections in keratinized tissues in humans and animals. This group of fungi is defined by their ability to digest keratin and encompasses a wide range of species. Classification of many of these species has recently changed due to genetic analysis, potentially affecting clinical diagnosis and disease management. In this review, we discuss dermatophyte classification including name changes for medically important species, current and potential diagnostic techniques for detecting dermatophytes, and an in-depth review of Microsporum canis, a prevalent zoonotic dermatophyte. Fungal culture is still considered the “gold standard” for diagnosing dermatophytosis; however, modern molecular assays have overcome the main disadvantages of culture, allowing for tandem use with cultures. Further investigation into novel molecular assays for dermatophytosis is critical, especially for high-density populations where rapid diagnosis is essential for outbreak prevention. A frequently encountered dermatophyte in clinical settings is M. canis, which causes dermatophytosis in humans and cats. M. canis is adapting to its primary host (cats) as one of its mating types (MAT1-2) appears to be going extinct, leading to a loss of sexual reproduction. Investigating M. canis strains around the world can help elucidate the evolutionary trajectory of this fungi.

Pilot Videodermoscopic Examination of Hair and Skin in Arabian Mare Horses During the Winter Season

Videodermoscopy is a novel, noninvasive technique used to examine the appearance of skin and its adnexa. The aim of this study was to assess specific dermoscopic parameters in Arabian purebred mares in particular areas of the body during the winter season. The study was performed in the winter season. Videodermoscopic evaluations of the hair and skin were performed over seven areas of the body: the forehead, mane, neck, chest, flank, croup, and tail. Twenty-one healthy, non-breeding Arabian mares aged 3 to 21 years were selected for the study. The Video-Dermatoscope Vidix 7 (Medici Medical SRL) equipped with a 5-Mpx camera, and the VX1 cover (contact type cap 3.5 cm) was used. The CellSens Dimension was used to perform the above-mentioned measurements. Videodermoscopy revealed marked pigmentary differences in the hair of gray Arabian mares with blood vessels visible on unpigmented skin. The density of the hair in one dermoscopy field of view ranged from 1,458 (croup) to 3,680 (head) hairs and the thickness of hair ranged from 52.70 (chest) to 87.45 µm (tail). Uniform group of horses consisting of one sex, one breed, and one season. When compared to previous studies, our findings demonstrated that the density and thickness of hair are contingent upon a horse's breed and body region.

Trichophyton species and Microsporum gypseum infection and fomite carriage in cats from three animal shelters: a retrospective case series

OBJECTIVES

The goal of this retrospective case series was to report on the clinical aspects of confirmed Trichophyton species and Microsporum gypseum infections in cats from three animal shelters.

METHODS

This was an observational retrospective study. Fungal culture and treatment data from three animal shelters was retrospectively reviewed to identify cats with dermatophytosis caused by Trichophyton species or M gypseum.

RESULTS

Among the three shelters only four cats were diagnosed with M gypseum dermatophytosis. With respect to Trichophyton species infections, there were six cases identified and treated in a 1 year period in one shelter, 13 cases over 13 years in the second shelter and 27 cases over 5 years in the third shelter. Four cases of M gypseum dermatophytosis were treated in the third shelter. Young cats were most commonly infected and the disease was most commonly diagnosed in the fall and winter months. Lesions were inflammatory and found predominantly on the head and neck. There was a rapid response to treatment in all cases; mean (n = 20) and median (n = 17) days to mycological cure were calculated from available data. Fungal culture data revealed fomite carriage without clinical evidence of infection for Trichophyton species (n = 43) cats and M gypseum (n = 37) cats.

CONCLUSIONS AND RELEVANCE

There is a paucity of clinical information about non-Microsporum canis dermatophytosis in shelter cats. This study data shows that Trichophyton species and M gypseum infections do occur but are uncommon. Based upon the rapid response to conventional treatment, these infections do not represent a treatment challenge, as most cats reached mycological cure within 3 weeks.

Evaluation of hair follicle parameters using TrichoScale Pro© in healthy dogs: a pilot study

BACKGROUND

Trichoscopy, in combination with image analysis software, is a readily available, efficient diagnostic tool for assessing hair follicle parameters of people in vivo. Systems designed for use in human dermatology must be evaluated and validated with animal skin/hair before they can be used for veterinary applications.

OBJECTIVES

To evaluate the use of a commercial software package for image analysis of canine hair follicles and to define hair follicle parameters.

ANIMALS

Thirteen client-owned healthy dogs.

METHODS

Trichoscopic images at x20 magnification were obtained from three shaved body sites (left dorsal head, left thorax, left flank) over a five day period, then analyzed by the software.

RESULTS

The image analysis software was able to identify microscopic changes in hair length on a daily basis, calculating a mean hair growth rate of 0.065 mm/day. Each of the three body sites had consistent hair growth rates across all days. Anagen and telogen percentages were consistent at each body site by Day 2 (48 h post-clipping). Data for mean hair thickness, and primary and secondary hair percentages also are reported.

CONCLUSIONS

Although it provides less useful data for canine hair coats than for human scalp hair, the system evaluated provides an easy, noninvasive, rapid means for assessing several important canine hair follicle parameters: daily hair growth rates, anagen and telogen percentages, primary and secondary hair percentages, and mean hair thickness. This diagnostic tool could serve to establish breed-specific hair coat standards, evaluating hair follicle changes in various canine alopecic conditions and monitoring coat-promoting treatments in dogs.

Comparing dermoscopy and histological examination of normal equine skin

BACKGROUND

Dermoscopy is a noninvasive diagnostic technique that allows visualization of structures of the superficial dermis not visible with the naked eye.

HYPOTHESIS/OBJECTIVES

To assess the usefulness and applicability of dermoscopy for evaluation of healthy equine skin.

ANIMALS

Twelve healthy horses from a research herd.

METHODS

Five regions (cheek, lateral neck, dorsum, flank and abdomen) were examined with contact dermoscopy using both nonpolarized and polarized light at both 17-fold and 24-fold magnification. These findings were compared to histological features of skin biopsies cut both longitudinally and transversely.

RESULTS

Using a hand-held dermatoscope with nonpolarized light, epidermal ridges were observed. Using polarized light, follicular openings and distinctly separate epidermal openings of sweat gland ducts were observed in some but not all individuals. Similarities were noted between histological and dermoscopic results.

CONCLUSIONS

Although not ideal for visualizing many structures in the superficial dermis of healthy equine skin, dermoscopy allowed visualization of epidermal ridges, hair shafts in the infundibular portion of the hair follicles and sweat gland duct openings. Dermoscopy could potentially be useful in the evaluation of diseases affecting the sweat glands, epidermis and hair shaft.

Diagnosis and treatment of dermatophytosis in dogs and cats.: Clinical Consensus Guidelines of the World Association for Veterinary Dermatology

BACKGROUND

Dermatophytosis is a superficial fungal skin disease of cats and dogs. The most common pathogens of small animals belong to the genera Microsporum and Trichophyton. It is an important skin disease because it is contagious, infectious and can be transmitted to people.

OBJECTIVES

The objective of this document is to review the existing literature and provide consensus recommendations for veterinary clinicians and lay people on the diagnosis and treatment of dermatophytosis in cats and dogs.

METHODS

The authors served as a Guideline Panel (GP) and reviewed the literature available prior to September 2016. The GP prepared a detailed literature review and made recommendations on selected topics. The World Association of Veterinary Dermatology (WAVD) provided guidance and oversight for this process. A draft of the document was presented at the 8th World Congress of Veterinary Dermatology (May 2016) and was then made available via the World Wide Web to the member organizations of the WAVD for a period of three months. Comments were solicited and posted to the GP electronically. Responses were incorporated by the GP into the final document.

CONCLUSIONS

No one diagnostic test was identified as the gold standard. Successful treatment requires concurrent use of systemic oral antifungals and topical disinfection of the hair coat. Wood's lamp and direct examinations have good positive and negative predictability, systemic antifungal drugs have a wide margin of safety and physical cleaning is most important for decontamination of the exposed environments. Finally, serious complications of animal-human transmission are exceedingly rare.

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

Alopecia areata (AA)-like disease is characterized by multifocal patchy hair loss in humans, rodents, dogs, and horses. Remarkable similarities between human and nonhuman AA cases have been reported in terms of clinical presentation, histology, and immune mechanisms of the disease. Canine AA-like lesions most often consist of well-demarcated alopecic patches, frequently but not only involving the face and the head, which extend to the ear pinnae and legs. In some cases, hair loss can have a more generalized distribution. As in humans, hair regrowth is most commonly spontaneous in canine AA-like disease and the resistant cases usually respond to glucocorticoids or cyclosporine treatment. Diagnosis of AA in veterinary medicine relies on presentation, histopathology, and immunohistochemistry and on regrowth following therapy. This case report describes the first dermoscopic evaluation of AA-like disease in a dog with a clinical presentation of symmetrical hair loss.