Canine Dermatology Case study module 6

1. CASE STUDY MODULE 6
9yr 5 month old male Boxer

2. CASE HISTORY
• Duration ~3months
• Worsening
• Pruritus
• Otitis externa
• Poor response to Convenia, dexamethasone and prednisolone

3. PRESENTING SIGNS

4. PRESENTING SIGNS

5. CASE WORK UP
• List your differential diagnosis
• List in order the further investigations you would perform

6. DIFFERENTIAL DIAGNOSIS BASED ON
PRESENTING SIGNS
• Pyoderma
• Superficial folliculitis
• Deep pyoderma
• Malassezia dermatitis
• Immune-mediated
• Drug induced pemphigus foliaceus
• Erythema multiforme
• Stevenson-Johnson syndrome
• Ectoparasitic
• Sarcoptic mange
• Demodicosis

7. FURTHER INVESTIGATIONS AND FINDINGS
• Skin scrapings
• Negative for demodex and sarcoptes
• Impression smears
• Neutrophils with few acanthocytes
• Neutrophils with intracellular coccoid bacteria
• Tapestrips
• Malassezia negative

8. CYTOLOGY
X 40 magnification X1000 magnification

9. REVISED DIFFERENTIAL DIAGNOSIS
• Immune mediated
• Pemphigus foliaceus
• Erythema multiforme
• Superficial staphylococcal pyoderma – MRSP or MRSA
?

10. WHAT FURTHER TESTS WOULD YOU
DO NOW?

11. FURTHER TESTS
• Culture and sensitivity
• S. pseudintermedius isolated sensitive to all antibiotics except
amoxicillin and oxytetracycline
• Histology
• Pustular dermatitis with acantholytic cells
• Consistent with pemphigus foliaceus

12. DIAGNOSIS
• Pemphigus foliaceus
• Drug induced or spontaneous
• Secondary staphylococcal infection

13. TREATMENT
• Prednisolone
• 2 mg/kg divided into two doses for 14 days
• 1.0mg/kg sid until no lesions
• Tapered to every other day
• Sebocalm shampoo
• Marbofloxacin 2mg/kg sid
• Step up flea control
• 2 weekly advocate 4 times
• Indorex to environment

14. FOLLOW UP – 4 MONTHS LATER
• Tapered prednisolone to 10mg eod
• Weekly sebocalm
• Monthly advocate on dog and monthly Frontline on cat
• No PF lesions so taper prednisolone further
• Increase in pruritus – allergic component
• Introduce atopica and reduce and attempt to stop prednisolone as signs
of PU/PD/PP
• Controlled lesions for 16 months then relapsed