Skin therapy 1

Question 1

4 steps to managing allergic skin disease

Answer 1

1. avoidance
2. medication to control pruritus and erythema
3. immunomodulation
4. control of secondary flare-factors
   * combination, tailored to individual*

Question 2

How well can allergens be avoided

Answer 2

1. fleas - possible?
2. food - YES
3. environmental - not really, house dust mites (dead can still be allergenic), epithelia of different species (only if exposure can be limited), pollens (seasonal)

Question 3

What does shampoo therapy do?

Answer 3

• remove allergens from skin
• improve skin/coat hygiene and care
• efficacy rarely documented
• owner compliance important

Question 4

Name 2 types of shampoo

Answer 4

• containing lipids, complex sugars, antiseptics (Allermyl, Virbac)
• oatmeal shampoo

Question 5

Options - medical tx of pruritus

Answer 5

POWERFUL (80% efficacy):

• GCs
• Ciclosporin (Atopica)
• (Tacrolimus: Protopic ointment)
• Oclacitinib

OTHERS (30% efficacy):

• antihistamines
• EFAs
• (chinese herbal medicine)
• (not recommended: progestagens (cats, pentoxifyllin, misoprostol)
• combination of above

Question 6

Adverse effects - GCs

Answer 6

• Immediate: PU/PD, polyphagia, restlessness

- Long-term: HAC, weight gain, CT

Question 7

How useful for topical GCs?

Answer 7

limited use in animals, Cortavance

Question 8

Outline oral GCs

Answer 8

• prednisolone (short-acting)
• anti-inflammatory dose (dog 0.5-1mg/kg/d, cat 1-2mg/kg/d)
• aim for long term control: lowest necessary dose given on alternate days - minimises adrenal suppression)

Question 9

How should you monitor a patient on GCs?

Answer 9

every 6 months perform haem and biochem and urine culture

Question 10

How does ciclosporin work?

Answer 10

• cacineurin-inhibitor
• targets TC response more than GCs although efficacy is comparabe
• slow onset of effect (4 weeks) - not for acute itch

Question 11

Adverse effects - ciclosporin

Answer 11

• transient V+D
• gingival hyperplasia
• hirsutism (increased hair growth)
• lameness
• EXPENSIVE

Question 12

Describe antihistamines

Answer 12

• little EBVM, up to 30%?
• try different types (each for 10-14d)
• chlorpheniramine (only one for cats), clemastine, hydroxyzine
• NL for animals at all

Question 13

What essential fatty acids are used for medical management of pruritus?

Answer 13

• N3 (fish oils) and N6 (plant oils) (eicosanoids)
• interact with arachidonic acid cascade
• more effective for seasonal disease?
• steroid sparing

Question 14

What is oclacitinib (Apoquel)?

Answer 14

• new product for medical management of pruritus
• inhibits JK-1 –> switches off itch but not reddness
• authorised in dogs >12 years
• adverse effects after 14 days

Question 15

Define ASIT

Answer 15

Allergen-specific immunotherapy

Question 16

Describe ASIT

Answer 16

• injection of allergen extract SC at increasing quantities and intervals to patients with AD
• PEOPLE: decreases inflammatory cells, Ig, modulation of TH1/TH2 response
• PREPARATION: aqueous, alum precipitated or glycerinated

Question 17

Efficacy - ASIT for AD

Answer 17

• full efficacy may take up to 9 months

- up to 50% (DOGS), higher in horses, unknown in cats

Question 18

How can individual allergens be identified for ASIT?

Answer 18

• INTRADERMAL TEST: mast cell bound IgE, requires GA

- IgE serology: allergen-specific IgE (most commonly)

Question 19

Define SLIT

Answer 19

= sublingual immunotherapy

• alternative to ASIT
• drops are sprayed under tongue so no injection

Question 20

PROS - ASIT and SLIT

Answer 20

• safe
• potential AEs (anaphylaxis) rare, no long term SEs
• infrequent tx (monthly)
• often more cost effective (esp large breeds)
• preventative not reactive

Question 21

CONS - ASIT and SLIT

Answer 21

• initial higher cost
• risk of anaphylaxis
• full efficacy may take several months
• compliance may drop with long term approach
• flare-factors need controlling during initial tx to allow full assessment of efficacy
• syringes dispensed to owner

Question 22

What are the most common flare-factors in AD?

Answer 22

• fleas
• other concurrent allergens (food, environmental)
• Staph pyoderma
• Malassezia dermatitis

Question 23

What should you say to owner in managing allergic skin disease?

Answer 23

• life-long implications
• no complete cure, overall management
• waxing and waning course of disease

Question 24

What neoplasia can be mistaken for allergic skin disease?

Answer 24

EPITHELIOTROPIC LYMPHOMA

Question 25

Describe epitheliotropic lymphoma

Answer 25

• Ddx allergic skin disease
• affects epidermis
• usually dogs 10+ years (allergy younger)
• exfoliative eryhtroderma (whole skin is red)
• digital pad involvement (unlike allergic skin disease where interdigital skin is affected)
• thus some aspects don’t fit exactly with typical hx of allergic skin disease so this should prompt consideration of this condition