Management options for atopic dermatitis

• What are the 4 ways to treat and manage allergic skin disease?

  Control inflammation + pruritus.

  Allergen avoidance & allergen-specific immunotherapy.

  Improve skin barrier

  Control flare factors.
• What anti-inflammatories and anti-pruritic drugs are available?

  Glucocorticoids (corticosteroids) - multiple actions.

  • Prednisolone
  • Dexamethasone

  Calcium inhibitors -> T-cell suppression:

  • Topical tacrolimus
  • Oral ciclosporin

  JAK inhibitor:

  • Oclacitinib (apoquel)

  Anti IL-31 monoclonal antibody

  • Lokivetmab (cytopoint)

  Antihistamines
• Glucocorticoids for pruritus

  Highly effective re-inflammation and pruritus, rapid onset (24 hour), inexpensive - but significant risk of side effects, especially with long term use.

  Vary in anti-inflammatory potency and duration of action, dependant on drug/ester/formulation. Also vary in mineralcorticoid action.
• What are the potential side-effects of glucocorticoids?

  Tend to increase with steroid potency, dose, duration.

  Short term:

  • Polydipsia, polyuria, polyphagia
  • Panting, lethargy.

  Long-term use:

  Systemic immunosupression

  • Infections (often undetected in bladder)
  • Failed wound healing.

  GI heamorrhage/gastric ulcers

  Iatrogenic HAC

  Diabetes mellitus
• What are the options for systemic glucocorticoids?

  Short acting solutions:

  • Useful for rapid onset short-acting effect - some licensed IV.
  • Occasionally dexamethasone solution orally for fractious cats - off label - use with care and informed consent

  Depot suspensions:

  • Some products (methylprednisolone acetate) with action <4-8 weeks but poor dose control. Most commonly used for fractious cats.
  • Diabetogenic and risk hypothalamic-pituitary-adrenal axis suppression with long term use.
• What are the options for oral glucocorticoids?

  They are the mainstay of dermatological GCCs

  • Usually prednisolone
  • Occasionally methylprednisolone (more expensive but less MCC effects).
  • Dose - anti-inflammatory dose needed for allergic disease
  • Start daily
  • Taper to the lowest effective alternate day dose if needed for maintenance.
  • Taper gradually - NEVER STOP SUDDENLY!!
• What are the options for topical glucocorticoids?

  Useful for focal treatment and to reduce use of systemic GCCs.

  Risk of systemic absorption and skin thinning with long term use:

  • Gloves must be worn
  • Advise owner relicensed maximun duration of therapy, especially on the thin-skinned areas.
• Lokivetmab (cytopoint)

  Specific action (selective blocking of IL-31):

  • Good safety profile and no effect on general immunity.
  • Rare anaphylaxis
  • Excellent antipruritic but minimal anti-inflammatory effect.
  • NB for allergic pruritus and dermatitis only, not for pruritus of non-allergic origin

  s/c injection q4 weeks; dogs only, rapid onset of action, effective in 75% dog.
• Oclacitinib (apoquel)

  Very commonly used for drug CAD - dogs only, minimun 1yo

  Effective in approximately 70% of cases.

  Rapid-onset effect (24h), considered safe for long term use.

  Excellent antipruritic, some inflammatory effect.

  NB for treatment of allergic pruritus and dermatitis only, not for pruritus of non-allergic origin.

  Minimal interaction with other drugs, though unlicensed for concurrent use with prednisolone or ciclosporin
• Ciclosporin

  Excellent anti-inflammatory and anti-pruritic.

  Licensed for dogs and cats, but costly.

  Effective (80% cases) but slow to work (1-2 months).

  • Initial concurrent use with 2-3 weeks of prednisolone or oclacitinib (off label)

  Oral product - q24h initially, but many taper to q48-72h once stable.

  T-cell suppressor:

  • Avoid use 2 weeks before/after vaccination.
  • Test cats for FeLV/FIV/Toxoplasmosis before commencing.
• What are the side effects of ciclosporin?

  Most commonly diarrhoea/vomiting, usually transient.

  Others e.g. anorexia, gingival hyperplasia, hirsuitism
• Allergen specific immunotherapy

  Administer small amount of relevant allergen to try to induce tolerance.

  Only treatment that can potentially alter the long term course of the disease.

  Immunotherapy vaccines made by selecting clinically relevant allergens:

  • Based on positive results from IDT or serum IgE testing.
  • Administration: subcutaneous, sublinguinal, intralymphatic
• Improving the skin barrier

  Topical moisturisers:

  • Colloidal oatmeal, aloe Vera, glycerin, urea, propylene glycol, ophytrium, lactic acid, sodium or ammonium lactate.

  Systemic essential fatty acids:

  • Supplements of high EFA diets.
  • NB 2-3 months to effect

  Essential oils
• Controlling of flare factors

  Good ectoparasite control

  Avoid overheating

  Control microbial populations:

  • e.g. antimicrobial shampoos/wipes/foams
  • For treatment and prevention
• What factors affect treatment choice?

  Patient:

  • Species, age
  • Clinical signs:
  • Area of body affected
  • Level of inflammation vs pruritus
  • Systemic health

  Drug:

  • Speed of response required
  • Product efficacy, safety

  Owner:

  • Expected compliance
  • Cost (including of monitoring)