Skin Therapy Flashcards
What are the four ways allergic skin disease is managed?
Avoidance
Medication to control pruritis and erythema
Immunomodulation
Control of secondary flare factors
What is important to always rule out?
Adverse food reaction
What are the issues with avoidance?
Is it possible to avoid fleas - need strict control regimen
Environmental allergens hard to avoid
Can use shampoos to remove allergens from skin but lacking in evidence and poor compliance
What are the options for medical treatment of pruritis?
Glucocorticoids, Ciclosporin, Tacrolimus ointment
Antihistamines, EFAs, Herbal medicine
Combination of the above
What are the advantages of glucocorticoids as an anti-pruritic medication?
Effective
Readily available
Frequently used
Cheap
What are the immediate adverse effects of glucocorticoid therapy?
PD/PU, polyphagia, restlessness
What are the long-term adverse effects of glucocorticoid therapy?
Hyperadrenocorticism, weight gain, connective tissue…
What can topical glucocorticoids be used to treat?
Hot spots and ears
What is the dosing for oral glucocorticoid therapy?
Prednisolone at 0.5-1mg/kg/day in dogs, 1-2mg/kg/day in cats
What is the aim for long-term control with glucocorticoid therapy?
Lowest necessary dose given on alternate days
What is the mechanism of action of ciclosporin?
Cacineurin inhibitor with more specific T-cell suppression than glucocorticoids
What is a disadvantage of ciclosporin over glucocorticoids?
Slow onset of effect at about 4 weeks so not for acute itch
Expensive
What are the adverse effects of ciclosporin?
Transient vomiting and diarrhoea
Gingival hyperplasia
Hirsutism
Lameness
What is the mechanism of action of oclacitinib?
Janus-kinase 1 inhibitor
What is the trade name for oclacitinib?
Apoquel
What is Apoquel licensed to treat?
Dogs over 12 months for the treatment of pruritis associated with allergic dermaitits and the clinical manifestations of atopic dermatits in dogs
What are the potential adverse effects of Apoquel?
4.6% diarrhoea, 3.9% vomiting, 2.6% anorexia, 2.6% new cutaneous/subcutaneous lumps, 2% lethargy
How are antihistamines used to treat pruritic skin disease?
Little evidence for efficacy but try different types for 10-14 days each
None licensed for use in animals
May be more effective in seasonal disease
Which essential fatty acids (EFAs) can be used to treat pruritic skin disease?
N3 (fish oils) and N6 (plant-derived oils) interact with the arachidonic acid cascade
What advantages can EFAs have when used to treat pruritic skin disease?
Safe
Steroid-sparing?
What is a disadvantage to using EFAs to treat pruritic skin disease?
Effect will take several weeks
What is allergen-specific immunotherapy (ASIT)?
Injections of allergen extract subcutaneously at increasing quantities to patients with atopic dermatitis
Aqueous, alum precipitated or glycerinated
How long does ASIT take to work?
May take up to 9 months for full effect
What is the efficacy of ASIT?
Up to 50% in dogs, higher in horses, unknown in cats
How are individual allergens identified for ASIT?
Intra-dermal skin test or IgE serology for allergen specific IgE
What is it important to keep in mind when performing an intra-dermal skin test/IgE serology?
Match test results to history and clinical signs as if it is a pollen allergy on the test but only reacts in winter it is unlikely to be the allergen causing the pruritis
What is sublingual immunotherapy (SLIT)?
Drops are placed under the tongue instead of injections with clinical improvement demonstrated in small studies and serological changes observed
What are the advantages of ASIT and SLIT?
Safety
Potential adverse effects - rarely anaphylaxis with no long term side effects (vs steroids)
Infrequent treatment required (monthy)
Often more cost effective especially in large breeds
Preventative rather than reactive
What are the disadvantages of ASIT and SLIT?
Initial cost
Risk of anaphylaxis (although small)
Full efficacy may not be seen for several months
Compliance may drop with long term approach
Flare factors need to be controlled during initial treatment to allow full assessment of efficacy
Syringes dispensed to owner (not for SLIT)
What are the EBVM recommendations for treatment of acute flares of cAD?
Identify and remove causes of flares
Non-irritating baths and topical glucocorticoids
Oral glucocorticoids and antimicrobials if needed
What are the EBVM recommendations for treatment of chronic flares of cAD?
Identify and avoid triggers where possible
Topical and oral glucocorticoids
Oral ciclosporin
Topical tacrolimus
ASIT should be offered to prevent recurrence of signs
What are the most commonly recognised flare factors for atopic dermatitis?
Flea control
Other concurrent allergens
Staphylococcal pyoderma
Malassezia dermatitis
Why is good client communication crucial in the treatment of canine atopic dermatitis?
Owner education of life-long implications and waxing and waning course of disease so don’t lose faith
Regular follow-up examination is required so pruritis levels are controlled adequately and to check on potential adverse effects of therapy (haem/biochem)
What needs to be considered when deciding which antibiotic to use?
Efficacy Delivery method Antimicrobial selection Side effects Length of treatment Cost
What are the two methods of antibiotic selection?
Empirical
Selection based on culture and sensitivity
How are antibiotics selected empirically?
Classically superficial pyoderma/folliculitis caused by S. pseudintermedius
Wet lesions are caused by gram negatives
Local knowledge of sensitivity patterns
What drugs can be used to treat superficial pyoderma?
Cefalexin (92% cure)or co-amoxy-clav (72% cure)
Clindamycin
Topical shampoos alone or in combination
What is the treatment used for deep pyoderma?
Based on culture and sensitivity
Whilst waiting for results use cefalexin for cocci and fluoroquinolone for rods
How long should treatment for pyoderma last for?
Superficial - 1 week past clinical cure
Deep - 2 weeks past clinical cure
What are the possible clinical causes of antibiotic ‘resistance’?
Wrong dose Compliance Absorption Underlying cause Resistance developed during treatment
What are the possible bacterial causes of antibiotic ‘resistance’?
Intrinsic resistance (natural trait) Acquired resistance (mutations..)
What is MRSP?
Meticillin-resistant Staphylococcus pseudintermedius
Gene encoding broad spectrum beta-lactam antibiotic resistance mecA positive (more resistant than MRSA)
What kind of infections does MRSP cause?
Superficial and deep pyoderma in dogs, cats, donkeys and horses
Septicaemia, UTI, pneumonia and wound infections
What is the relevance of MRSA in veterinary practice?
Most pet isolates identical to human hospital lineages
Animals as a reservoir
Effective drugs licensed
Ethical concerns if same antimicrobial used in humans
Owner perceptions
Personal and clinic hygiene - risk if immunocompromised
What are the treatment options for MRSP?
Systemic therapy if in vitro susceptibility identified
Topical therapy alone
Off-licensed treatment with exotic antibiotic
Which topical treatments can be used against MRSP?
Fusidic acid
Chlorhexidine
Benzoyl peroxide
Which exotic antibacterial drugs could be used against MRSP?
Apramycin Amikacin Vancomycin Chloramphenicol Rifampin
When should exotic antibacterial drugs be used?
Only after contacting an expert for advice on clinical aspects and comprehensive infection control strategy
How are antimicrobials used responsibly against staph?
Diagnosis of bacterial infection, pathogen and any underlying causes
Focus on hygiene and good owner education
Are systemic antimicrobials required?
Targeted use, narrow spectrum for 1st time pyoderma and good follow-up
