Page 220 - Cote clinical veterinary advisor dogs and cats 4th

Atopic Dermatitis 93

Acute and Chronic Treatment concomitantly with other drugs (antibiotics, • Beneficial in approximately 70% of cases
antifungals, and allergy medications).
Because of the multifactorial nature of atopic Antihistamines: • ASIT is usually considered to treat atopic
VetBooks.ir involves combinations of multiple modalities • Not to be used as sole therapy in severe cases or nonseasonal pruritus, when antipruritic Diseases and Disorders
dermatitis if there is a long allergy season
dermatitis, the best therapeutic approach often
therapy does not provide sufficient relief, or
(topical/systemic and short-term/long-term)
nor in acute phase
when allergy medications are contraindicated.
individualized for each patient.
20%-30% of cases
Corticosteroids: • Limited benefit; may alleviate pruritus in • Response to therapy is individualized; may
• Highly and rapidly effective for controlling • Responses are unpredictable; several com- be seen as early as 1 month or may take up
pruritus associated with environmental pounds should be given in 2-week trials. to a year.
allergies (short-term and long-term use) • May be used in combination with other • Maintenance treatments are given as often
• May be administered orally or topically (if therapies as needed to maintain the response (usually
pruritus is localized) • Side effects include drowsiness, lethargy, and every 1-3 weeks), and usually therapy is
• Although topicals are considered safer, they nervousness. Reducing the frequency of lifelong. Sublingual immunotherapy is
can cause local and systemic adverse effects administration and dose may minimize these administered 6 days a week.
(skin absorption). effects.
• Dogs: prednisone or prednisolone at an initial • Oral antihistamines that may have some Drug Interactions
daily dose of 0.5-1 mg/kg/day before weaning benefit for dogs include hydroxyzine Drugs that inhibit cytochrome P450 enzymes
to an alternate-day schedule is the first choice 2.2 mg/kg PO q 8-12h, diphenhydramine (azoles, macrolides, avermectins, corticosteroids)
glucocorticoid for atopic dermatitis. 2.2 mg/kg PO q 8-12h, chlorpheniramine will increase cyclosporine blood levels.
• Cats: prednisolone at an initial daily 0.4 mg/kg q 8-12h, amitriptyline 1 mg/kg
dose 1-2 mg/kg/day or dexamethasone PO q 12h PROGNOSIS & OUTCOME
0.1-0.2 mg/kg/day, then q 48-72h, • Antihistamines that may be useful in cats
respectively. include chlorpheniramine 2 to 4 mg/CAT q • With environmental allergy, it is imperative
Cyclosporine: 12h, amitriptyline 0.5-1 mg/kg PO q 12h. that clients understand that the allergy is
• Cyclosporine is an effective, slow-acting (2-3 Essential fatty acids (EFAs): likely to affect the pet (and owners) for life.
weeks) calcineurin inhibitor and potent • No clear evidence supporting real benefit of • With good client compliance and individual-
immunomodulatory agent. supplementing with EFA, but can be part ized therapy, > 90% of cases can be satis-
• Microemulsion type (Atopica): 5 mg/kg of long-term management factorily managed, particularly with the
(dog) or 7 mg/kg (cat) PO q 24h • May alleviate pruritus in 10%-20% of cases. recent availability of effective systemic
• Between 50% and 65 % of dogs will have They are given for 4-12-week trials, usually antipruritic therapies.
a satisfactory reduction in pruritus. About not as sole therapy.
half of dogs that benefit from daily • Omega-3 EFA in oral capsule form as a PEARLS & CONSIDERATIONS
cyclosporine will continue to do well on supplement (eicosapentaenoic acid 30-40 mg/
alternate-day therapy. kg/day) or in food may theoretically help Comments
• Treatment is expensive, especially for manage pruritus by decreasing the produc- • Canine atopic-like dermatitis is a similar
medium- or large-breed dogs. tion of proinflammatory mediators. disease in which IgE cannot be detected
• Vomiting is the most common side effect, Topical antipruritic therapy: (negative results for serology and intradermal
although gingival hyperplasia, hypertrichosis, • A cool bath has an antipruritic effect from tests).
and secondary infections (viral, bacterial) the cooling effect of evaporation and rehy- • Hypoallergenic diet may be helpful in some
have been noted. drating the skin. atopic patients.
• Cats that have a negative Toxoplasma titer • Mild cleansing or moisturizing (e.g., colloidal • Topical and/or systemic antipruritic therapy
should be confined indoors. oatmeal) shampoos +/− conditioners may should be part of the therapy, at least initially,
Oclacitinib: be beneficial. when ASIT is indicated.
• Oclacitinib (Apoquel), a fast-acting Janus • Spot-on or spray barrier-restoring products • Routine follow-up examinations, including
kinase inhibitor, blocks the action of some (e.g., ceramides, phytosphingosine) are of physical examination, CBC, chemistry
proinflammatory and pruritogenic cytokines, undetermined benefit. profile, and urinalysis, are recommended
especially interleukin-31 (IL-31). • Topical glucocorticoids (Cortavance, Genesis) every 6-12 months for dogs on long-term
• Dogs: 0.4-0.6 mg/kg PO q 12h for up to are useful for focal areas of pruritus and to therapy, especially a corticosteroid.
14 days and then administered q 24h prevent flare-ups. • Canine atopic dermatitis has a strong genetic
• A flare-up of clinical signs may be noticed • Topical 0.1% tacrolimus (Protopic), a component, and affected dogs should not
when reduced to once daily. calcineurin inhibitor, is useful for focal be used for breeding.
• About 70% of dogs experience a reduction areas of pruritus. The U.S. Food and Drug
in pruritus of at least 50% (useful for short- Administration (FDA) has issued a public Technician Tips
term and/or long-term management). health advisory warning of a potential • Client counseling is very important before
• Not approved for use in cats nor dogs cancer risk. If used, apply short-term or starting treatment; unrealistic expectations
younger than 12 months intermittently. and lack of understanding are causes of client
• Adverse reactions are uncommon; leukopenia • Physical barriers (e.g., Elizabethan collar, dissatisfaction.
is reported. T-shirts, bodysuits, boots) may be helpful • The regular use of topical antimicrobials
Lokivetmab: in preventing self-trauma and secondary (shampoos or sprays) and regular baths may
• Leukivetmab (Cytopoint), a caninized mono- infections help control microbial overgrowth and wash
clonal antibody (mAb) that targets canine ASIT: out allergens caught by hairs.
IL-31, is a safe and very effective therapy • Subcutaneous or oral (sublingual immuno-
for controlling clinical signs associated with therapy) administration of a gradually SUGGESTED READING
atopic dermatitis. increasing dose of allergens that produced Hensel P, et al: Canine atopic dermatitis: detailed
• Dogs: 2 mg/kg SQ every 4-8 weeks. DO positive reactions on allergy testing, are guidelines for diagnosis and allergen identification.
NOT USE IN CATS. present in the patient’s environment, and BMC Vet Res 11:196-209, 2015.
• No specific adverse events have been reported are consistent with the patient’s allergy AUTHOR: Frédéric Sauvé, DMV, MSc, DES, DACVD
with its use nor when administered season. EDITOR: Manon Paradis, DMV, MVSc, DACVD

www.ExpertConsult.com