Skin Therapy - Allergy

Question 1

4 main ways to manage allergic skin disease?

Answer 1

1. avoidance
2. medication: pruritis and erythema
3. immunomodulation
4. control of 2* flare factors

Question 2

Which type of allergy is easiest to avoid?

Answer 2

food

• fleas potentially
• house dust mites very difficult to avoid (hard to eradicate and dead mites still allergenic)

Question 3

Is shampoo therapy advocated?

Answer 3

• may remove allergens from skin
• allermyl (lipids, sugars, antiseptic)
  + others (oatmeal episoothe)
• but not just SHAMPOO
• rare evidence but not doing harm, may be halpful
• monitor

Question 4

What are the main 3 most efficacious options for medical tx of pruritis?

Answer 4

1. Glucocorticoids
2. Ciclosporin [atopica has flavouring, cyclavance and sporimmune more recent] (+ topical ciclosporin Tacrolimus [protopic])
3. Oclacitanab [Apoquel] (lic but not available atm)

Question 5

What additional therapies may be used at medical tx of pruritis?

Answer 5

> antihistamines
- better for seasonal use
- preventative (stops MC degranulation, not useful if already degranulated) 
- 30% effecivity 
- weeks to build up to theraputic doses 
> EFAs 
- do no harm
> chinese herbal medicine, progestagens (cats) side eeffects, pentoxyfylline and misoprostol not very good, but people will know about them/use them)

Question 6

Advantages of GC use? Most common drug and dose rate?

Answer 6

• effective, readily available, cheap
• prednisolone (Short acting)
• anti-inflammaotry dose dog 0.5-1mg/kg/d cat 1-2mg/kg/day (aim long term control LOWEST POSSIBLE DOSE alternate days to prevent adrenal suppression)

Question 7

Adverse effects of GCs? Alternative form?

Answer 7

• immediate: PUPD, polyphagia, restlessness
• long-term: hyperadrenocorticism, ^weight, connective tissue problems
  > topical GCs for localised lesions eg. Fusiderm (+fusidic acid ABx) Cortavance (hydrocortisone)

Question 8

What is ciclopsorin? Efficacy? Side effects?

Answer 8

• Cacineurin-inhibitor
• more targetting T-cell suppression than GCs
• efficacy = GCs (~80%)
• freq side effects = GCs (prednisolone)
  > VD+, gingival hyperplasia, hirsuitism, lameness
  > hepato- or nephrotoxicity not at therapeutic doses
  > ^ risk neoplasia? V immune surveillance
  > expensive
  > slow onset of action

Question 9

How regularly should chronic cases on long term steroids be checked up?

Answer 9

monitor q6months

• haem/biochem
• urine

Question 10

How long ciclosporin onset of action?

Answer 10

4 weeks dog or 7 weeks for cat

not for acute itch

Question 11

Mechanism of action of Apoquel? Licensed?

Answer 11

(Oclacitinib) Janus-kinase 1 inhibitor (IL31 cytokines) pruritis but NOT inflam
- lic dogs > 12 months (tx pruritis ssociated with allergic dermatitis and atopic dermatitis) currently unavailable

Question 12

Adverse effects of Oclacitinib?

Answer 12

• doesnt tx inflammation so 2* bacterial pyoderma still common
• monitor
• VD+/anorexia/lumps/lethargy been reported

Question 13

Egs antihistmaines?

Answer 13

• chlorpheniramine (only one for cats)
• clemastine
• hydroxyzine
  > try different types fro 2 weeks each

Question 14

Which antihistamines are licensed for animal use? Are tehy advocated?

Answer 14

NONE!!!

• human piriton get from pharmacy
• may be effective
• steroid sparing

Question 15

What types of EFA are usually used?

Answer 15

fish oils N3 and plant oils N6

- arachidonic acid cascade

Question 16

When are EFA advocated? When should they not be used?

Answer 16

• steroid sparing
• safe
  > do not use during food trials (gelatin)
  > take few weeks to kick in so long term

Question 17

What types of EFA are available?

Answer 17

• vet (start with these)

- shop bought

Question 18

Options for cheap tx plan for atopic dermatitis?

Answer 18

• GCs
• EFAs
• antihistamines?
• shampoos
  > compliance necessary for success!

Question 19

How often should GCs dose be reduced?

Answer 19

~ 3 months

Question 20

What is ASIT? Effects? Efficacy?

Answer 20

• injections of allergen extract (SC) at increasing quantities
• in humans v inflammaotry cells, Ig, modulation of Th1/Th2 response [missing out Langerhans cells alleviates some of immune response?]
• aqueous, alum precipitated or glycerinated available
• injected at ^ doses, ^ intervals ~ 9 months (ending with ~1ml/month, owners can do at home)
• dogs 50% horses higher

Question 21

Cost of ASIT?

Answer 21

• £300 per allergy testing

- vax ~ £200

Question 22

How is ID of individual allergens?

Answer 22

• intradermal test for mast cell bound IgE

- IgE serology for FcERIa (more common 1st opinion)

Question 23

What main allergens are tested for?

Answer 23

• house dust mites
• epithelia
• pollens
• NOT FOODS (IgG and IgE to food are physiological not allergic)

Question 24

How should allergy tests be used?

Answer 24

Combine with clinical signs (eg. time of year etc.)

Question 25

Long term plan using ASIT?

Answer 25

• 9 months

- review: if working, continue for life; if hasnt helped then stop

Question 26

What alternative ROA for immunotherapy is now available?

Answer 26

Sublingual (SLIT)

Question 27

Pros and cons of ASIT and SLIT?

Answer 27

> pros
- safety
- injection monthly only 
- may be cost effective 
- preventative not reactive
- good for large dogs 
> cons
- anaphylaxis (1st time escpecially) rare
- initial cost
- full efficacy ~ months
- compliance may be poor 
- flare factors need control during initial tx to assess efficacy 
- syringes dispensed to owner

Question 28

Most commonly recognised flare factors?

Answer 28

• flea/parasites
• concurrent allergens (fleas, food, environment)
• staphylocollal pyoderma
• malasezzia dermatitis

Question 29

What must owners be made aware of with allergic skin disease?

Answer 29

• waxing and waning disease
• life long
• follow up [ruritis levels and adverse effects of therapy

Question 30

What neoplasia may mimic atopic/allergic skin disease? How would you differentiate?

Answer 30

- Epitheliotropic lymphoma
> depigmentation of nasal planum
> exfoliative erythroderma (all skin not just predilection sites) 
> old age of onset 
> foot pads involved (not interdigital) 
> plaques and nodules 
> dx: histo, poor prog -> chemo