Acne in Cats: Veterinary Consult PDF

14 Blackwell’s Five-Minute Veterinary Consult A Acne—Cats (bacterial, yeast, or dermatophytes), or to Severe cases may warrant treatment with diag...

14 Blackwell’s Five-Minute Veterinary Consult A Acne—Cats (bacterial, yeast, or dermatophytes), or to Severe cases may warrant treatment with diagnose neoplasia. isotretinoin (Accutane) or cyclosporine, PATHOLOGIC FINDINGS modified (Atopica®). ­ BASICS Demodicosis—isoxazoline parasiticides. Mild disease—follicular distention with OVERVIEW keratin (comedo), hyperkeratosis, and CONTRAINDICATIONS/POSSIBLE Inflammatory dermatitis affecting the chin follicular plugging, most often associated INTERACTIONS and lips. with allergic dermatitis. Benzoyl peroxide and salicylic acids—can Symptoms may be recurrent or persistent. Severe disease—mild to severe folliculitis be irritating. SIGNALMENT and perifolliculitis with follicular pustule Some wipes contain alcohols that can be Cats. formation leading to furunculosis and irritating. Prevalence for sex, age, or breed not pyogranulomatous dermatitis. Systemic isotretinoin—use with caution, if reported. Bacteria and Malassezia in these lesions are animal will not allow application of topical considered secondary invaders and not medications; potential deleterious side effects SIGNS causative agents. in human beings (drug interactions and Cats may have a single episode, a life-long Demodex mites can be primary agents of teratogenicity); container should be labeled recurrent problem, or a continual disease. this disease. for animal use only and kept separate from Frequency and severity of each occurrence vary with the individual. human medications to avoid accidental use; Comedones, mild erythematous papules, currently difficult to obtain for animal serous crusts, and dark keratin debris develop patients. on the chin and less commonly on the lips. ­ TREATMENT Swelling of the chin. Initial treatment—gentle clipping and Severe cases—nodules, hemorrhagic crusts, soakings to soften crusts. pustules, cysts, fistulae, severe erythema, Food elimination diet. ­ FOLLOW-UP alopecia, and pain. Intradermal allergy testing. Monitor for relapses. Pain often associated with bacterial Continue one or a combination of the Maintenance cleansing programs can be furunculosis. therapies listed below until all lesions have used to reduce relapses; affected cats are likely CAUSES & RISK FACTORS resolved. to have variable numbers of comedones Discontinue treatment by tapering life-long, which often are just cosmetic, and Precise etiology unknown; often is associated with allergic skin diseases; may be a disorder medication over a 2- to 3-week period. treatment is not necessary. Recurrent episodes—once the recurrence of keratinization, poor grooming, abnormal sebum production, immunosuppression, viral rate is determined, an appropriate maintenance infection, or stress. protocol can be designed for each individual. Continual episodes—life-long maintenance treatment necessary. ­ MISCELLANEOUS PREGNANCY/FERTILITY/BREEDING Systemic isotretinoin should not be used on ­ DIAGNOSIS breeding animals. DIFFERENTIAL DIAGNOSIS ­ MEDICATIONS ­Suggested Reading Hypersensitivity (atopy, flea bite, food, Jazic E, Coyner KS, Loeffler DG, Lewis TP. contact). DRUG(S) OF CHOICE An evaluation of the clinical, cytological, Bacterial folliculitis. Topical infectious and histopathological features of Demodicosis. Shampoo—once or twice weekly with feline acne. Vet Dermatol 2006, Malassezia infection. antiseborrheic (sulfur-salicylic acid, benzoyl 17(2):134–140. Dermatophytosis. peroxide, or ethyl lactate). Miller WH, Griffin CE, Campbell KL. Acne. Neoplasia of sebaceous or apocrine glands. Cleansing agents—benzoyl peroxide, salicylic In: Muller & Kirk’s Small Animal Eosinophilic granuloma. acid, chlorhexidinephytosphingosine. Dermatology, 7th ed. St. Louis, MO: Medicated wipes. Elsevier, 2013, pp. 640–642. CBC/BIOCHEMISTRY/URINALYSIS Antibiotic ointment—mupirocin 2%. Rosencrantz WS. The pathogenesis, N/A Other topicals—clindamycin or erythro­ diagnosis, and management of feline acne. OTHER LABORATORY TESTS mycin solution or ointment. Vet Med 1993, 5:504–512. N/A Combination topicals—benzoyl peroxide- Werner AH, Power HT. Retinoids in IMAGING antibiotic gels (e.g., Benzamycin). veterinary dermatology. Clin Dermatol N/A Topical retinoids—tretinoin (e.g., Retin-A® 1994, 12(4):579–586. 0.01%): gel more effective because of better White SD. Feline acne and results of DIAGNOSTIC PROCEDURES penetration. Skin scrapings—demodicosis. treatment with mupirocin in an open In severe inflammatory periods 10–14 days clinical trial: 25 cases (1994–96). Vet Bacterial culture—resistant infection. of oral prednisolone (1–2 mg/kg q24h) may Fungal culture—dermatophytosis. Dermatol 1997, 8:157. help to reduce scar tissue formation. Author David D. Duclos Cytology—bacteria, Malassezia. Biopsy—rarely needed; necessary in Systemic Consulting Editor Alexander H. Werner selected cases to characterize changes such as Antibiotics—amoxicillin with clavulanate, Resnick cystic follicles, to differentiate acne from cephalosporin, or fluoroquinolone. other diseases such as demodicosis, infections  Canine and Feline, Seventh Edition 15 Acne—Dogs A IMAGING Gentamicin/steroid-containing ointments N/A for the ears can be applied to localized lesions DIAGNOSTIC PROCEDURES twice daily; most useful for lesions on the ­ BASICS chin, as the pet cannot lick this area. Constant Impression cytology will help determine if OVERVIEW bacteria or yeast are present. long-term use over months may cause alopecia Also (more correctly) muzzle folliculitis and Skin scrape—demodicosis. and cutaneous atrophy: limit frequency and furunculosis. Dermatophyte culture—dermatophytosis. duration of application. Chronic inflammatory disorder of the chin Bacterial culture and sensitivity testing—in Systemic and lips of mostly young animals. patients with suppurative folliculitis and Antibiotics based on culture and sensitiv- Characterized by folliculitis and furunculo- furunculosis that are nonresponsive to initial ity—when indicated (e.g., cephalexin, sis; almost never comedogenic as seen in “true antibiotic selection. 22–30 mg/kg PO q12h for 2–4 weeks). acneiform” lesions of human beings. Biopsy—histologic confirmation for cases Oral corticosteroids: tapering dosages of Recognized almost exclusively in short- in which diagnosis is in question. prednisolone (initial 0.5 mg/kg/day) to coated breeds. reduce significant inflammation; not for Genetic predisposition, local trauma, and PATHOLOGIC FINDINGS Clinical signs and histopathologic findings continued use. allergic disease often play a role. Evaluate for and manage concurrent are diagnostic. SIGNALMENT Characterized histopathologically by allergic/atopic skin disease. Dogs, often younger, sometimes puppies. folliculitis and furunculosis. CONTRAINDICATIONS/POSSIBLE Predisposed short-coated breeds—boxer, Bacteria—not always isolated from lesions INTERACTIONS Doberman pinscher, English bulldog, Great in early stages. Topical steroids—may cause adrenal Dane, Weimaraner, mastiff, Rottweiler, As disease progresses, papules enlarge and suppression and thinning of skin with German shorthaired pointer, pit bull terrier. rupture, promoting a suppurative folliculitis frequent or constant use. SIGNS and furunculosis. Ventral chin and lip margins may have few to numerous erythematous papules and sometimes bullae. These may coalesce to form plaques. ­ FOLLOW-UP ­ TREATMENT Initial lesions are inflammatory and sterile; Reduce behavioral trauma to the chin (e.g., PATIENT MONITORING bacteria may not be isolated and lesions may Continue antibiotics until lesions have rubbing on the carpet, chewing bones that not respond to antibiotics. increase salivation). healed. Advanced lesions may contain pus or blood, Repeat bacterial culture/sensitivity if lesions Frequent cleaning with chlorhexidine- indicating secondary deep bacterial folliculitis containing pads, shampoos, or solutions can worsen. and furunculosis. Discontinue topical corticosteroids when be helpful, but instruct owners not to scrub at Lesions may be pruritic, some are painful the area. possible. on palpation, but most are nonpainful and Gentamicin/steroid-containing ointments EXPECTED COURSE AND PROGNOSIS nonpruritic. for the ears work well on the chin when Long-term topical treatment may be Chronic and pruritic lesions may become applied twice daily. required. hyperpigmented, lichenified, scarred, and If topicals are not helpful by themselves, Chronic scarring may be prevented by early alopecic. add oral antibiotics based on positive cytology and aggressive therapy. CAUSES & RISK FACTORS and culture and sensitivity testing. Several short-coated breeds appear to be Severe cases may necessitate short courses of genetically predisposed to acne. Lesions may oral steroids. be worse in allergic individuals. Evaluate for underlying allergic/atopic disease and institute proper therapy for ­ MISCELLANEOUS diagnosis and control of these diseases; control ASSOCIATED CONDITIONS of allergic disease may permit resolution of Allergic/atopic disease may cause and muzzle folliculitis and furunculosis. exacerbate this condition. ­ DIAGNOSIS Instruct owners to avoid squeezing the ­Suggested Reading DIFFERENTIAL DIAGNOSIS lesions; trauma may make inflammation Miller WH, Griffin CE, Campbell KL. Dermatophytosis. worse. Muzzle folliculitis and furunculosis. In: Demodicosis. Muller & Kirk’s Small Animal Dermatology, Juvenile cellulitis. 7th ed. St. Louis, MO: Elsevier, 2013, pp. Contact dermatitis. 201, 640. With other symptoms, consider allergic/ atopic disease as playing a role. ­ MEDICATIONS Author Melissa N.C. Eisenschenk Consulting Editor Alexander H. Werner CBC/BIOCHEMISTRY/URINALYSIS DRUG(S) Resnick N/A Topical Acknowledgment The author and editors OTHER LABORATORY TESTS Daily cleaning with chlorhexidine-containing acknowledge the prior contribution of Karen N/A pads, shampoos, or solutions can be helpful; Helton Rhodes. instruct owners not to scrub at the areas.