DERMATOLOGY DILEMMAS Kimberly Coyner, DVM DACVD Petie the Pit Bull - History • 1.5 yr SF Pitbull, adopted 4 mo ago from shelter • Chronic otitis since obtained, unresponsive to systemic and topical steroids and antibiotics, unresponsive to lamb/rice diet based on allergy serology • Referred for TECA Petie the Pit Bull - Problems Otitis Predisposing factors: Pinnal or canal conformation, moisture Primary causes: Allergy, otic parasites, foreign body/mass, endocrine, autoimmune, keratinization disorder Secondary factors: Bacterial or yeast infection of outer +/- middle ear, scarring or proliferative changes, inappropriate treatment Petie the Pit Bull - Diagnostic plan • • Ear swab for mites: negative Otic cytology: Malassezia Petie the Pit Bull-Treatment Plan Treat secondary infections • • Yeast otitis externa: Otomax, EpiOtic cleaner, prednisone Yeast otitis media: Ketoconazole Flush ears • • • • Pre-treat with pred/keto to open canals Examine canals/tympani R/O foreign body/mass Remove accumulated exudate which perpetuates infection Identify and treat underlying allergic cause • • Hypoallergenic diet trial +/- Intradermal allergy testing Peetie the Pit Bull - Keys Poor steroid-responsiveness is characteristic of food allergy Otitis can be the only symptom of allergy It is essential to flush the goo and treat otitis media if infection is chronic Food allergy is diagnosed and treated with a hypoallergenic diet trial The Old Itchy Chow - History 11yr NM Chow X 1.5 year history of generalized nonseasonal pruritus Poor response to antibiotics, antihistamines, steroids, z/d diet, and allergy immunotherapy based on serology Old Itchy Chow - Problems Pruritus Infection Bacterial, fungal Parasite Alopecia/Hyperkeratosis Fleas, scabies, otodectes, demodex Allergy Pemphigus, cutaneous LSA Bacterial infection Fungal infection Demodicosis Keratinization disorder Food, atopy Other hepatocutaneous, zincresponsive Endocrinopathy Immune mediated Old Itchy Chow – Diagnostic Plan Skin scrape for mites Skin cytology for infection +/- Bacterial and fungal cultures CBC/Chemistry Panel/Thyroid panel All WNL at rDVM Skin biopsies P. S. The owners are itchy So are the residents of the retirement home that the dog visits weekly Old Itchy Chow - Treatment Ivermectin 0.3mg/kg PO weekly x 6 weeks (pre-treatment heartworm test negative) Sebolux shampoo weekly to reduce crusting followed by lime sulfur dips weekly x 4 weeks as antipruritic/antiparasitic Cephalexin 22mg/kg PO BID x 30 days Prednisone 0.5mg/kg PO daily x 5 then taper Notify medical personnel at retirement home Old Itchy Chow - Keys Pruritus starting after 5 yrs of age less likely atopy Poor steroid-responsiveness of pruritus is inconsistent with atopy, and more consistent with food allergy, infection, or scabies Atopy is diagnosed by exclusion of other causes of pruritus, not by a blood or skin test History and PE/distribution of lesions are very important Start with the basics: skin scrape, cytology, trial antiparasitic therapy on every case even if SS - Moab History Neutered male 8 year old labrador Adopted at 6 months of age from shelter Presented for pruritus and recurrent pyoderma History of seasonal ‘ear infections’ History First few years ‘sores’ were in ears only • Sores used to develop every fall; last few years sores have become more frequent • Itching and sores have become constant past 6 months • Some improvement with antibiotics but never complete resolution •Some improvement with food trial but owner not consistent • History Previous Diagnostic Tests CBC/Chemistry Cytology Negative Skin scrape Cocci, yeast DTM WNL Negative Biopsy Previous Therapies Multiple antibiotics Multiple ear topicals Food trial Corticosteroids Multiple injections Topicals Lymphoplasmacytic dermatitis Dermatological Examination Ears: Pinnae multiple crusted pustules with patchy alopecia, excoriations and erythroderma Paws erythroderma with multiple patchy crusted pustules and papules Dorsal abdomen/thorax multiple crusted papules/pustules and epidermal collarettes Groin/medial thighs multiple crusted pustules and epidermal collarettes Differential Diagnosis Allergy • Pyoderma • Dermatophytosis • Parasite • Autoimmune • Mycosis fungoides • Diagnostics Performed Cytology Skin scrape DTM Repeat biopsies Diagnostic Results Cytology Skin scrape Negative Cultures Negative DTM Multiple inflammatory cells, eosinophils, cocci, rods and acantholytic cells Resulted in Methicillin resistant Staph. pseudointermedius sensitive to doxycycline Repeat biopsies Consistent with Pemphigus foliaceus with secondary pyoderma Treatment Treat infection: Oral antibiotics Doxycycline 10mg/kg BID daily for 6 weeks Topicals Bathe daily with Chlorhexiderm Apply ResiKetoChlor Lotion daily Treatment Corticosteroids Started as first line of immunosuppression Cyclosporine Azathioprine Doxycycline/Niacinamide Chlorambucil Mycophenolate Junior History Neutered male 9 year old Shih Tzu Acquired from breeder at 12 weeks Onset of pruritus 2 years prior Pruritus is constant and severe Progressive hair loss, erythema, crusted sores that now affect entire body Best response per owner to steroid injections but only helped for few days Now losing weight, PU/PD History Previous Diagnostic Tests CBC/Chemistry Elevated WBC Elevated cholesterol Previous Therapies Antibiotics Antihistamines Corticosteroids DTM Negative Dermatological Examination Generalized lymphadenopathy Generalized skin lesions Patchy alopecia with seborrhea, hyperkeratosis, hyperpigmentation and comedones Large crusted and exudative plaques Ears swollen canals with oozing purulent discharge Differential Diagnosis Food hypersensitivity • Parasitic dermatitis • Infectious • Endocrinopathy • Autoimmune disease • Diagnostics Performed Cytology Skin scrape Culture DTM CBC/Chemistry/UA/UC/ Thyroid Panel Diagnostic Results Cytology Skin scrape Multiple demodex mites in all life stages Culture Large numbers of cocci, rods and yeast Resulted in multiple bacteria; all multiple sensitivities DTM Negative Diagnostic Results CBC/Chemistry/UA/UC/ Thyroid Panel CBC: Elevated WBC (consistent with stress leukogram) Chemistry: Elevated Alkaline Phosphatase, ALT, Cholesterol, Triglycerides, Total Protein, and Globulins UA: Decreased USG; Proteinuria; Pyuria and struvite crystals UC: E. Coli Thyroid Panel: Elevated TSH, decreased T4 (ed) Treatment Oral antibiotics Cephalexin 22mg/kg every 12 hours Topicals Multiple options Ear topicals should not have steroids as will exacerbate demodicosis Treatment Options Ivermectin 0.4-0.6mg/kg PO SID Mitaban dips weekly Clip long coated dogs Interceptor/Sentinel 1-2mg/kg PO SID Advantage Multi q 1-2 weeks Do not combine with Comfortis/Trifexis Do not use in herding breeds MDR-1 test: http://www.vetmed.wsu.edu/depts-VCPL/ Best for mild cases, young dogs Treatment for 2-3 negative skin scrapes 4 weeks apart, average 3-4 months Imperative to control immunosuppression Treatment Begin thyroid supplementation If difficult to regulate, rule out hyperadrenocorticism or atypical Cushing’s Claudius the Cat - History 5yr NM DSH Several year history of pruritus/self trauma directed at the right shoulder Prior steroid injections and topical steroid/antibiotics would reduce pruritus but “sore never healed” History of positive DTM in past, but no improvement with Ketoconazole Currently on z/d prescribed for prior history of diarrhea, occasionally gets other cat’s food 2 months ago, “sore” was excised and Convenia injections given post-op, but wound dehissed and now wound is worse than ever Claudius - Problems Pruritus Hypersensitivity Parasite, food allergy, atopy Infection Bacterial, fungal Psychogenic, neurogenic • Coccidiodomycosis, crypto, sporotrichosis Iatrogenic • Actinomyces, Nocardia, Mycobacteria Deep fungal infection Less Common Ulcerated wound Deep bacterial infection Chronic topical steroids Neoplasia SCC Claudius – Diagnostic Plan Skin scrape/cytology Tissue cultures Aerobic, anaerobic, mycobacterial, fungal Biopsy for histopathology Stricter hypoallergenic diet trial Claudius - Results Tissue culture: MRSA, resistant to all antibiotics except sulfa drugs, amikacin and chloramphenicol Histopathology: Allergic dermatitis Claudius - Treatment Advised owner of zoonotic concerns, need for gloves/hand washing after handling cat, contact own MD for recommendations Discontinue topical steroids Primor X 3 weeks then recheck Wound care daily + Collasate E. Collar/T shirt/Soft Paws Continue stricter hypoallergenic diet Claudius – 1 week later Claudius – 3 weeks later Cytology at 3 week recheck Claudius - Outcome Added mupirocin at 3 week recheck and continue Primor for 1 more week Phone report Week 4: pruritus persists at shoulder lesion only, added topical Tacrolimus and oral antihistamines Discussed IDAT, CsA if milder symptomatic therapy not helpful At last recheck, pruritus is satisfactorily controlled as long as medications are used consistently and diet is strictly enforced Claudius - Keys Start with the basics, skin scrape/cytology on every case Don’t use Keto in cats, get accurate fungal ID on every DTM Bacterial culture indicated if poor response to empiric antibiotics Tissue culture more accurate than swab for deep lesions Avoid chronic topical steroids In multi cat households, its best to feed all cats the hypoallergenic diet Roscoe - History 5 yr. old NM pitbull 1.5 yr. history of chronic mildly pruritic truncal dermatitis, only partially/temporarily responsive to steroids and antibiotics, unresponsive to a hypoallergenic diet trial Prior biopsy results: chronic furunculosis Roscoe - Problems Pruritus Infection Parasite Allergy Draining tracts/scarring Deep bacterial infection Deep fungal infection Demodicosis w/ bacteria Solar dermatitis Roscoe – Diagnostic Plan Skin scrape for mites Skin cytology for infection Dermatophyte culture Biopsy for bacterial culture Aerobic, anaerobic, mycobacterial Treat infection for 3 weeks then biopsy for histopathology Dermatopathologist Roscoe - Results Skin scraping: negative for mites. Skin cytology: pyogranulomatous inflammation with intra and extracellular cocci. Skin culture: Staph. intermedius sensitive to cephalosporins Dermatophyte culture: negative Histopathology: Solar dermatitis and chronic furunculosis, localized areas of epithelial atypia Roscoe - Treatment Cephalexin x 3 months, Hexadene/ResiChlor 1-2x/wk NSAIDS prn for pain Sun avoidance Indoors 10am-5pm Sunscreen when outside Sunsuit (designerdogwear.com) Roscoe – One month recheck Roscoe – Six month recheck Roscoe – Six month recheck Roscoe – 6 month recheck New problems: Non-healing crusted preputial erosions unresponsive to antibiotics, skin masses on groin Biopsy of preputial lesion: SCC in situ Excisional biopsies of skin masses: SCC and dermal HAS, completely excised Treatment: Aldara/imiquimod QOD x 4 weeks on prepuce, Solaraze/diclofenac cream on groin, continue sun avoidance Roscoe – 1 and 3 months later Roscoe – 18 month recheck Roscoe - Keys Solar dermatitis can mimic allergic dermatitis Solar dermatitis is often more painful than pruritic, usually restricted to white areas, and can occur in areas not typical for allergies Clear up infection before biopsy, and send to dermatopathologist with complete history, lesion description and distribution Even with future sun restriction, dog is on skin tumor watch for the rest of its life due to prior sun damage Buckles - History 12yr old NM Bichon Several month history of pruritic crusting dermatitis on trunk, tail, legs and feet, minimally responsive to antibiotics (currently on Baytril) and Atopica Several year history of seizure disorder controlled with Pb Became diabetic 6 months ago, controlled with insulin Elevated liver enzymes also developed 6 months ago, ultrasound/aspirate: reactive hepatopathy, currently treated with SamE, milkthistle Buckles - Problems Alopecia/Crusting dermatitis Pruritus Infection Parasite Allergy Other Pemphigus, cutaneous LSA Bacterial infection Fungal infection Demodicosis Keratinization disorder hepatocutaneous, zinc-responsive Endocrinopathy Immune mediated Buckles – Diagnostic Plan Skin scrape/cytology Dermatophyte culture Bacterial skin culture CBC/Chemistry panel/thyroid panel All WNL at rDVM except moderately elevated ALP/ALT Biopsy/histopathology Trunk, leg, feet in separately labeled jars Dermatopathologist Recheck liver ultrasound Buckles - Results Skin scrape: negative for mites Skin cytology: degenerative neutrophils, intra and extracellular cocci Dermatophyte culture: negative Bacterial culture: Abundant growth of Coag – Staph, resistant to fluoroquinolones Biopsy: Leg crusts - pyoderma; Foot crusting – hepatocutaneous syndrome; Trunk crusts - EM with pyoderma Recheck liver ultrasound/aspirate: unchanged reactive hepatopathy Buckles – Treatment Pyoderma: Hydrotherapy to remove crusts while anesthetized for biopsy, Simplicef x 6 weeks, Mupirocin to crusted lesions BID, Hexadene/ResiChlor 2x/wk EM: Pentoxifylline, discontinue all other nonessential drugs, consider restarting CsA MEN: Change from PB to KBR, add eggs to diet to increase protein, consider IV amino acids Buckles - Outcome Crusted lesions on legs, tail and feet resolved within 6 weeks, as did pruritus Targetoid lesions on trunk slowly improved over 3 months Buckles continues to do well on pentoxifylline and KBR Buckles - Keys Start with the basics: skin scrape/cytology Culture indicated if poor response to empiric antibiotics Coag – Staph can be pathogenic Use a dermatopathologist and give complete history, lesion description and distribution EM is treated with drug withdrawl and immunomodulating drugs Pentoxifylline, CsA, steroids MEN/hepatocutaneous syndrome is not always fatal if the cause of the hepatopathy can be identified and withdrawn before irreversible liver damage develops Maxine 12yr old SF Maltese 9 month history of mildly pruritic crusting dermatitis and alopecia Unresponsive to antibiotics and steroids Prior rDVM labwork showed elevated liver enzymes and low T4, ACTH stim borderline, Soloxine prescribed with no improvement Maxine is also PU/PD and is losing weight Maxine – Differential Diagnosis • Folliculitis • • • • Metabolic • • • • Bacterial Demodex Dermatophyte Hypothyroid Cushing’s disease Hepatocutaneous Neoplastic • Cutaneous lymphoma Maxine – Diagnostic Plan Skin scraping for mites Skin cytology for infection Dermatophyte culture Skin biopsy Recheck ACTH stimulation Abdominal ultrasound Maxine – Skin Cytology Maxine – Trichogram Maxine – Dermatophyte Culture Maxine – DTM result: M. Canis Maxine – Biopsy Result: Dermatophytosis Maxine – PS: the owner has lesions too Maxine – Treatment Plan Fluconazole 5-10mg/kg PO SID Lime sulfur dips weekly Identify and treat underlying immunosuppressive disorder Environmental decontamination Wash bedding and hard surfaces with 0.5% bleach Frequent vaccumming Discard cat trees, grooming appliances Instructed owner to obtain toothbrush cultures on the 2 other dogs and 3 cats in the household, ALL cultures were positive for M. canis, advised owner to obtain oral and topical antifungal medications from rDVM Maxine - Outcome Unfortunately the owner declined further workup of Maxine’s metabolic disease and declined therapy for the other pets in the household beyond antifungal shampoos At 4 week recheck, Maxine’s dermatitis was unchanged, she was continuing to lose weight and she was then lost to follow up Maxine - Keys Start with basic workup on every case Toothbrush culture helps reduce false negative dermatophyte cultures Use flat dermatophyte culture: DermatoPlate S-Duo from Vetlab Supply at www.VetLab.com Fungal ID important to confirm true positive DTM and identify fungal species Culture in-contact pets In chronic refractory dermatophyte cases, investigate underlying immunosuppressive disease or asymptomatic carriers in household