12 December 2017
Itching to get started
A 14 month old Flat Coated Retriever was referred for investigation following a 4 month history of pruritus.
Investigations included -
- Skin scrapings
- Bacterial and dermatophyte cultures
- A 10 week elimination diet trial and re-challenge with the usual food
- Intradermal skin testing
- IgE environmental serology
- Scabies serology
- Faecal parasite screening
- Comprehensive flea control
- Treatment of bacterial infection
After 12 weeks diagnosis was confirmed as atopy, adverse food reaction (food allergy), secondary pyoderma and suspected flea allergy.
Initial management consisted of continued rigorous flea control, diet restriction and avoidance of triggering environmental allergens – house and storage mites, pollens, moulds and cat epithelium. The client also carried out regular emollient bathing. Pruritus flare ups were treated with 7 days of glucocorticoids and any pyoderma flares with appropriate antibiosis.
Having conscientiously followed this path the pruritus reduced somewhat but remained a concern for the owners, particularly in the summer time on camping trips, so it was decided to embark on desensitisation using allergen specific injectable immunotherapy containing the 16 allergens previously identified on intradermal and serological testing. After the initial induction course, the injections were given every 3-4 weeks for maintenance alongside the original management protocol.
Over time the need for antibiotic and oral steroid declined. Any flare ups could be treated with topical rather than systemic glucocorticoids. Three years later the skin is normal with no pruritus 95% of the time. There are still some mild flares in the summer months but these respond with prompt topical glucocorticoids. There has been no requirement for oral steroids or antibiotics for 2 years. Immunotherapy is ongoing at maintenance dose and will continue until 12 months have passed without clinical signs. There is an expectation that immunotherapy may be required for life.
New developments open up the possibility of different management options in these cases that may be more effective, convenient and safe.
Firstly we have antiseptic wipes and cleaning pads which are quick, simple and economical to use, replacing time consuming bathing while still effectively reducing skin allergen and microbial loading. Other easy to use topicals can enhance skin hydration and barrier function.
Oclacitinib is a safe drug effective in the long term management of many allergic dogs. Speed of onset is rapid and side effects are few. Contrast this with glucocorticoids which have numerous side effects and allergen specific immunotherapy, which although very safe, can take up to 9 months to show benefit, and there is a significant failure rate.
The latest exciting development is lokivetmab, a caninised antibody directed against the important cytokine Il-31. The reported safety profile is excellent and speed of onset rapid. It will be interesting to see how this revolutionary new product fits into the way we treat these demanding cases.
It is always imperative not to forget that successful management of any skin case is dependent on accurate diagnosis, not the indiscriminate use of new drugs. Diagnosis can be challenging, but very achievable with a thorough and logical approach.