Drugs for atopic dermatitis and auto-immune skin disease Flashcards
Describe the principles of multimodal therapy of atopic dermatitis
Control of inflammation and pruritus
Allergen avoidance and allergen-specific immunotherapy (ASIT)
Improving the skin barrier
Control of flare factors
What are the treatment options for controlling inflammation and pruritus in atopic dermatitis?
Glucocorticoids
Oclacitinib
Lokivetmab
Ciclosporin
Antihistamines
Topical glucocorticoids
Describe the use glucocorticoids in treating atopic dermatitis
Rapid, cheap, anti-inflammatory action
Significant side effects with long term use
Prednisolone (oral) for dogs, cats, horses
Dexamethasone (IV/IM) for horses
Use at anti-inflammatory dose then taper to lowest effective dose over 48hrs
What are the side effects of long-term glucocorticoid use?
Endocrine & Metabolic:
- Iatrogenic Cushing’s disease (PU/PD, panting, potbelly).
- Diabetes mellitus (insulin resistance).
- Adrenal suppression (risk of Addisonian crisis if stopped abruptly).
Gastrointestinal:
- Gastric ulcers (↓ mucus production).
- Hepatopathy (elevated liver enzymes, fatty liver).
Musculoskeletal:
- Muscle atrophy & weakness (catabolic effects).
- Osteoporosis (bone resorption, fractures).
Dermatologic:
- Thin skin, poor wound healing (collagen breakdown).
- Alopecia & comedones (especially in dogs).
Immune System:
- Immunosuppression (↑ infection risk).
- Delayed wound healing (↓ inflammation).
Behavioural Changes:
- Polyphagia (↑ appetite, obesity risk).
- Restlessness, aggression, or lethargy.
Other:
- Hypertension (↑ sodium retention).
- Corneal ulceration (delayed healing, ↑ infection risk).
Describe the use of oclacitinib in atopic dermatitis therapy
Apoquel - oral - dogs
Blocks JAK-1 pathway
Good antipruritic + some anti-inflammatory action
Safe in long term
Describe the use of lokivetmab in atopic dermatitis therapy
Cytopoint - monthly injection - ONLY DOGS
Monoclonal antibody vs IL-31 - very targeted therapy - good safety profile
Good antipruritic but minimal anti-inflammatory action
Describe the use of ciclosporin in atopic dermatitis therapy
Oral - dogs + cats
Potent anti-inflammatory but onset of action too slow for acute flare
Very costly
Describe the use of topical GCCs in atopic dermatitis therapy
for localised lesions in short term
How can the allergen causing atopic dermatitis be identified?
Intradermal testing or IgE serology can be used to identify relevant non-dietary allergens once clinical diagnosis made
Describe allergen-specific immunotherapy (ASIT)
Administer small amounts of relevant allergen to try to induce tolerance
Only option that addresses underlying cause (cf controlling clinical signs)
Up to 12 months to assess efficacy
If effective, long term treatment usually required
Give examples of treatments used to improve the skin barrier in atopic dermatitis
Topical moisturisers e.g., colloidal oatmeal, aloe vera, glycerin
Oral/topical essential fatty acids
Essential oils
Describe how flare factors can be controlled in atopic dermatitis therapy
Control microbial populations - e.g. antimicrobial shampoos/wipes/foams
Good ectoparasite control
Avoid overheating
What are the aspects of autoimmune skin disease therapy?
Induction
Titration
Maintenance
Monitoring
Describe the aspect of induction in auto-immune skin disease therapy
Rapid control of lesions:
- systemic treatment usually required
- Glucocorticoids at immunosuppressive doses (prednisolone, dexamethasone)
- continue induction until most lesions healed and no new lesions for 2 weeks
- adjunctive treatment added if poor response after 10 days
Describe the titration aspect of auto-immune skin disease therapy
Taper glucocorticoids to lowest effective maintenance dose (slower than atopic dermatitis to reduce risk of relapse)
Adjunctive treatments used as lesions often recur as glucocorticoid dose reduces
Give examples of adjunctive treatments added to glucocorticoids to help maintain clinical control of auto-immune skin disease lesions
Azathioprine - not for cats!
Chlorambucil
Mycophenolate mofetil
Ciclosporin - esp for T-cell-mediated diseases
Oclacitinib
Gold salts
Describe the maintenance aspect of auto-immune skin disease therapy
Gradually taper therapy until clinical signs just recur to establish lowest effect dose
Increase dose to regain control => taper back to lowest effective dose for maintenance
If possible - reduce glucocorticoid to alternate day therapy to minimise side effects
What disease is this?
Pemphigus foliaceus of the cat pinna
Describe the monitoring of auto-immune skin disease therapy
Monitor:
- lesion control
- side effects of drugs (blood tests etc.)
