Douglas J. DeBoer, D.V.M., Diplomate A.C.V.D. School of Veterinary Medicine University of Wisconsin-Madison Parasites Infections Allergy Pemphigus Acne Indolent ulcer Neck ulcers Flea Allergy Dermatitis Cheyletiella Contagious demodicosis in a shelter
Diagnosis by therapy Monthly applications of fipronil or selamectin or isoxazoline Controls all parasites, even Demodex in the case of fluralaner Mosquito bite dermatitis Skin Cytology Direct impression (if moist) Collection with spatula or cellophane tape Quick hematology stain Classical dermatophytosis Chin Acne due to dermatophytosis
Feline Herpesvirus I After respiratory infection, virus dormant in trigeminal ganglion and rarely recrudesces due to stress, immunosuppression, etc. Pemphigus-like lesions due to dermatophytosis Feline Herpesvirus I Persistent, severe, ulcerative facial dermatitis: BIOPSY! Viral inclusion bodies often, but not always seen or hard to see advise laboratory! PCR may be possible (tissue sample) Consider therapeutic trial of famciclovir 90 mg/kg PO BID for 3+ weeks Old dose, 125 mg per cat BID; recent pharmacokinetic data shows very limited oral bioavailability and need for the higher dose Food or environmental Diet trial mandatory for feline head/neck pruritus Ulcerative to necrotic to plaquelike lesions on face Pruritic or nonpruritic May look like eosinophilic granuloma
Facial dermatitis Caseous Paronychia Bridge of nose, periocular, pinnae Footpads (peeling appearance) Caseous paronychia Body lesions Prolonged history of cycles of improvement/worsening Always confirm by biopsy Most cases respond readily to steroids Prednisolone, 2-3 mg/kg/d until remission, then taper very slowly Most cases probably idiopathic Defective cornification in follicle or sebaceous duct leading to plugging, then secondary infection Speculative causes Dermatophytosis Type of food bowl Food allergy Failure of chin grooming Treatment Treat secondary bacterial infection with antibiotics, if present Daily facial hygiene (benzoyl peroxide or salicylic acid shampoo) If recalcitrant: topicial tretinoin, 0.025% gel or cream twice daily until remission, then once every 1-2 days if needed Persian cats (genetic?) More severe form of acne? Comedones and crusts extend beyond chin to facial folds and preauricular areas Diagnostic evaluation as above, to rule out known underlying causes Most cases idiopathic Symptomatic treatment as for feline acne
Skin scrapings, hair plucking, flea combing NEG Routine flea control, monthly selamectin Dermatophyte culture NEG Cytology for infections many yeast organisms and bacteria found in debris around facial folds Amoxicillin-Clavulanic acid for 3 weeks Fluconazole for 3 weeks Chlorhexidine-Miconazole shampoo to face and body RESULTS: 50% decrease in pruritus Worsened once off therapy Re-institute topical therapy Hypoallergenic diet trial NO IMPROVEMENT Is this allergies? Is this a manifestation of AD in cats? Allergy in cats can have a wide variety of pruritic presentations. Initial diagnosis based on clinical appearance Cytology Remove surface debris, impression smears Eosinophils = tentative diagnosis Look for cocci, especially intracellular If present, treat for 2+ weeks with amoxi-clav Treatment IF otherwise healthy, young animal, ONE course of corticosteroids 20 mg methylprednisolone acetate injection, every 2 weeks for a total of 3 injections IF something is not typical (especially severe, recalcitrant to therapy, recurrent) search for underlying cause! Biopsy (check for FHV1) Evaluation for allergic disease
Treatment of Recalcitrant Disease Cyclosporine A (Atopica) 10-12 mg/kg daily for 4 weeks, then taper?