facial alopecia, scaling and erosions in a jack russell terrier author: ross bondeditor: david lloyd...

Facial alopecia, scaling and erosions in a Jack Russell terrier

Author: Ross BondAuthor: Ross Bond Editor: David LloydEditor: David Lloyd

© European Society of Veterinary Dermatology © European Society of Veterinary Dermatology


History - 2

HistoryHistory

• Dog lives in rural environment

• Lesion began as focal area of erythema and scaling caudal to nasal planum

• Progressed caudally over face despite therapy


Clinical signs - 1

SignsSigns

• Severe skin disease; lesion well-demarcated

• Smooth-silvery skin at healing areas rostrally

• Alopecia, scaling, erosions

• Nasal planum unaffected


How would youapproach this case?

SignsSigns

• What are the next steps you would take?

• Make a list of your principle differential diagnoses

• List any samples you would collect

• List any tests you would perform to assist in making a definitive diagnosis


Tests - 1

DifferentialsDifferentials

• Principle differential diagnoses• Dermatophytosis• Demodecosis• Deep pyoderma• Pemphigus foliaceus


Tests - 2

TestsTests

• Diagnostic tests• Skin scrapings• Wood’s light examination• Fungal and bacterial cultures• (Skin biopsy)


Results - 1

TestsTests

• No evidence of parasites & fungal elements on microscopy

• No fluorescence on Wood’s light examination

• Fungal growth evident on mycobiotic agar within 7 days of incubation


Results - 2

TestsTests

• White colonies with granular texture

• Dark tan / brown reverse pigment

• On microscopy, numerous microconidia and thin-walled cigar-shaped macroconidia

• Trichophyton mentagrophytes (granular form)

Fungal culture: Sabouraud’s dextrose agar, 5 days


What is yourdiagnosis?

TestsTests

• Do the investigations permit a definitive diagnosis?

• Are there any additional investigations which you think may need to be done?


Diagnosis

TestsTests

• Dermatophytosis caused by T. mentagrophytes

• Historical and clinical features strongly suggestive, supported by culture results

• Skin biopsies confirmed hair shaft and follicle invasion by fungal elements


How would you deal with this case?

• What is your prognosis?

• How will you advise the owner?

• What treatment would you consider?

TestsTests


Prognosis

TestsTests

• Prognosis is good• However, lengthy antifungal therapy is often

needed with Trichophyton infections in dogs


Therapy

TherapyTherapy

• Griseofulvin orally at 50 mg/kg (divided twice daily)

• Enilconazole (Imaverol) emulsion applied every 4th day

• Good clinical response after 8 weeks of therapy, but repeat cultures still positive

• Cultures negative and complete clinical response after 12 weeks of treatment, which was withdrawn at this time

• No relapse over a 6 month follow-up period


Comment -1

NotesNotes

• Owner’s lesions were present in this case, illustrating the zoonotic potential of canine dermatophytosis

• Jack Russell terriers are predisposed to sylvatic dermatophytosis in the U.K.

• The peripherally expanding, well-demarcated lesions on the face were suggestive of dermatophytosis


Comment -2

NotesNotes

• Lesions of dermatophytosis vary in appearance and severity

• Severely inflamed Trichophyton lesions on the face are misdiagnosed as pemphigus foliaceus

• Absence of focal crusted lesions (“footprints” of vesicopustules) and nasal planum involvement made PF much less likely in this case


Review

NotesNotes

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facial alopecia, scaling and erosions in a jack russell terrier author: ross bondeditor: david lloyd...

Documents

screen history

clinical signs

tests white colonies

days slide

prednisolone slide

history dog lives

lengthy antifungal therapy

days of incubation slide