Itch, Ears & Allergies Lunch & Learn

A comprehensive set of flashcards covering the framework of pruritus, otitis diagnosis and treatment, and atopy management in dogs and cats based on Dr. Andrea Caspary's lecture notes.

What are the four main categories of differentials in the Itchy Patient Framework?

Parasitic, Infectious, Allergic, and Other(endocrine etc)

What are five parasitic differentials for pruritus?

Fleas, Sarcoptes, Demodex, Cheyletiella, and Ear mites

What are three infectious differentials for pruritus?

Bacterial pyoderma, Malassezia dermatitis, and Dermatophytosis

List four allergic differentials for pruritus.

Flea allergy dermatitis (FAD), Environmental (atopy), Food adverse reaction, and Contact allergy

What 'Other' differentials should be considered for itch?

Endocrine (hypothyroid, Cushing's), Autoimmune (Pemphigus), Neoplasia, and Behavioral/psychogenic

What is the number one cause of pruritus in dogs?

Flea allergy dermatitis (FAD)

What is the first thing a New Grad should confirm in an itchy dog before other diagnostics?

Flea prevention compliance

What body distribution is typical for atopy in dogs?

• Feet

• Face

• Ears

• Groin

What body distribution is characteristic of Flea Allergy Dermatitis (FAD) in especially Canines?

Dorsal lumbar

What distribution pattern should make you think of Scabies?

Elbows and ears

If other pets or people are affected by itching, what should you suspect?

Contagious conditions such as:

• Sarcoptes

• Ringworm

• Cheyletiella

Why must a novel protein trial be strict?

Because it only works with strict elimination of all other proteins

What three aspects of prevention compliance should be verified?

• Product

• Frequency

• Whether it is used year-round versus seasonal

In lesion recognition, what is a macule or patch?

A flat color change

How is a papule defined?

A solid elevated lesion less than $1\,cm$

What is a pustule?

A pus-filled elevation

What is a vesicle or bulla?

A fluid-filled elevation

What is an epidermal collarette a sign of?

A post-pustule lesion, often indicating pyoderma

What is lichenification?

Thickened skin usually caused by chronic itch or trauma

What does hyperpigmentation indicate in the context of skin?

Chronic inflammation

What are the two main types of alopecia mentioned?

Self-induced versus follicular

What are three differentials for focal distribution patterns?

Trauma, ringworm, and folliculitis

What are two differentials for multifocal distribution patterns?

Pyoderma and demodicosis

What are three differentials for generalized distribution patterns?

Atopy, food allergy, and endocrine disease

When is Tape Prep best used for cytology?

• Greasy/waxy skin (yeast cases)

• Skin folds

• Interdigital spaces

• Surface bacteria

It can be used on an intact surface where no open lesion is needed

Steps for performing a Tape Prep

1. Press acetape to the skin surface for 3-5 seconds

2. Stick the tape on a slide and place a drop of blue stain (fixative) on the slide

3. No cover slip needed

4. Scan at 40x

5. Scan at 100x

When is an Impression Smear best used for cytology?

• Moist or exudative lesions

• Pustules

• Erosions

• Ulcers

• Epidermal collarettes

• Suspected pyoderma or pemphigus

Steps for performing an Impression Smear?

1. Press glass slide directly onto lesion (don't smear — press and lift)

2. For pustules: nick surface, press slide into expressed contents

3. Heat fix or air dry → stain with 3 step Diff-Quik

4. Look for: Bacteria (cocci, rods), neutrophils, yeast, acanthocytes

(pemphigus)

What is the golden rule for every skin lesion in the clinic?

Every skin lesion gets a cytology, every time

What are the three steps of the Otitis Externa approach?

1. Identify, 2. Treat, 3. Follow up

How to perform an Ear Cytology

1. Roll swab gently in aural canal

2. Roll swab on glass slide — don't smear

3. Heat fix or air dry, then stain (Diff-Quik)

4. Scan on 10x first, 40x for organisms

5. Then scan 100x with oil

What does finding cocci in clusters indicate on ear cytology? What is the first line of tx

Staphylococcus

TX:Florfenicol (Claro)- last 30days

or

Aminoglycosides;

1. Gentamicin (Mometamax, Otomax, Easotic)

2. Neomycin (Tresaderm)

What does finding cocci in chains indicate on ear cytology? What is the first line of tx

Streptococcus

TX: Florfenicol (Claro)- lasts 30days

or

Aminoglycosides:

1. Gentamicin (Mometamax, Otomax, Easotic)

2. Neomycin (Tresaderm)

List three rod-shaped bacteria found on ear cytology.

• Pseudomonas

• E-coli

• Klebsiella

What are three first-line treatments for rods in the ear?

• Polymyxin (Surulan)

• Orbifloxacin (Posatex)

• Enrofloxacin (Baytril Otic)

What organism is described as footprint-shaped or peanut-shaped? What is the first line of tx.

Malassezia (Yeast)

TX:DuOtic or Conzol 1%

What does finding neutrophils plus bacteria in the ear indicate? What systemic tx?

Infection and inflammation

TX:Systemic inflammatory control like Apoquel

What could WBCs without organisms in the ear canal mean?

Foreign body, immune issue, or allergy

TX: Further workup

Medicated ear cleaners/ flushes

Triz EDTA

1. It disrupts the cell membrane of gram-negative bacteria and enhances topicals

2. Great for Rods

Malacetic Ultra

1. Contains hydrocortisone, ketoconazole and ceramide complex to restore damaged barrier.

2. Great for prevention

When is systemic treatment indicated for otitis?

• Otitis media/interna

• Proliferative/stenotic canals

• Deep canals unreachable topically

Which oral antibiotics are used for Gram+ systemic otitis?

Amoxicillin-clavulanate

Which oral antibiotic targets Staph systemically in the context of ears?

Clindamycin

Which oral antifungals are used if yeast is severe or unresponsive?

Fluconazole or itraconazole

What is the monitoring requirement for oral Ketoconazole?

Watch liver enzymes

What is the short-course treatment for stenotic ear canals?

Prednisone

What is the dexamethasone protocol for inflammatory ears?

Dex SP drops in the ear every other day for $14\,days$

What are feline ear mites, how do they present and how to tx.

Otodectes cynotis

1. Most common cause in young cats.

2. Bilateral

3. Dark, crumbly coffee ground discharge. Intensely pruritic.

4. Check ALL cats in household.

TX:Selamectin (Revolution) topically. Treats the whole cat, not just the ear

What is feline yeast otitis, and how to tx.

Yeast (Malassezia)

1. Brown waxy discharge.

2. Usually secondary to allergy or polyp.

3. Cytology shows peanutshaped organisms.

4. Responds well to antifungals.

TX: Clotrimazole or Conzol 1% drops, Tresaderm

What is the warning regarding canine ear drops in cats?

Many are off-label for cats and one must watch for ototoxicity

If a cat has bilateral otitis, what is the first suspected cause?

Ear mites

What is the typical age of onset for canine atopy?

$$1-3\,yrs$$

Atopy is defined as a diagnosis of ________.

Exclusion

List 7 clinical signs in the canine atopy checklist.

1. Onset age $1-3\,yrs$

2. Pruritus: Often before lesions

3. Face/feet/axillae affected

4. bilateral ear involvement (not always otitis)

5. Lesion free dorsal lumbosacral area

6. Positive response to anti-inflammatories

7. Family history

What are the 5 steps of a Canine atopy workup

1. Confirm & optimize flea prevention

   1. All pets in house. Year-round. Even if you 'never see fleas.'

2. Treat secondary infections

   1. Skin & ears.

   2. You can't assess base pruritus with active infection.

3. Consider Sarcoptes

   1. Trial treatment with selamectin or isoxazoline if any doubt.

4. Food elimination trial (8 weeks)

   1. Novel protein or hydrolyzed. STRICT. No treats, flavored meds.

5. Diagnose atopy

   1. Allergen testing (intradermal or ELISA) if pursuing ASIT.

Long-Term Allergy Management options

1. Apoquel (oclacitinib)

   1. JAK Inhibitor

2. Cytopoint (lokivetmab)

   1. Monoclonal Antibody

3. ASIT

4. Allergen Immunotherapy

PROS

• Only disease-modifying tx

• Long-term desensitization

• May reduce other meds

CONS

• Slow (6–12 mo)

• Requires allergy testing

• Not 100% effective

Steroids

Corticosteroids

PROS

• Cheap, very effective

• Good for acute flares

• Useful short-term

CONS

• Side effects limit long use

• PU/PD, Cushing's risk

• Avoid as sole chronic tx

New Grad Tip: Cytopoint + Apoquel can be used together during flares. Frame it for clients as layered control, not failure.

What are the pros and cons of Apoquel (oclacitinib)?

PROS

• Fast onset (4–24 hrs)

• Excellent for daily use

• Well-tolerated long-term

CONS

• Daily oral medication

• Immunomodulatory effects

What are the pros and cons of Cytopoint (lokivetmab)?

PROS

• Injection q4–8 weeks

• Excellent client compliance

• Very safe profile

CONS

• Requires vet visit

• Variable duration

Which atopy medication is described as the only disease-modifying treatment?

Allergen Immunotherapy (ASIT)

How long does ASIT take to be effective?

$$6-12\,mo$$

What are three side effect risks of long-term steroid use?

PU/PD, Cushing's risk, and weight gain

Can Cytopoint and Apoquel be used together?

Yes, specifically during flares

What feline reaction pattern consists of tiny scabs that feel like sandpaper?

Miliary Dermatitis

What are the three components of the Eosinophilic Granuloma Complex?

Indolent ulcer (lip), eosinophilic plaque (ventral), and eosinophilic granuloma (linears)

What is the primary differential for Feline Symmetrical Alopecia?

Psychogenic versus allergic

Which feline reaction pattern is often associated with food allergy?

Head & Neck Pruritus

What is the preferred steroid for cats between prednisone and prednisolone?

Prednisolone

What should be checked before starting a cat on Cyclosporine (Atopica)?

FeLV/FIV status

Is Apoquel labeled for use in cats?

No, its use is currently off-label

Why should you open an allergy appointment with validation of the client's frustration?

It builds trust as allergic cases are often chronic and frustrating

Why should you frame the allergy workup as a systematic 'process' of exclusion?

It prevents 'why isn't this working' conversations and demonstrates expertise

What is the goal of atopy treatment: control or cure?

Control

What was the first move for Case A (Golden Retriever with seasonal foot licking)?

Confirm flea prevention and check ears/feet for secondary infection (cytology)

What was the concern for Case B (Labrador with acute pruritus and 3 other itchy dogs)?

Sarcoptes (Scabies)

What are common mistakes for new grads regarding atopy?

Diagnosing atopy before ruling out fleas or treating infections

Why is booking an otitis recheck essential?

Treatment is not completion; if it isn't booked, it won't happen

Why should secondary pyoderma be treated before starting Apoquel?

Apoquel will provide partial improvement, but you won't know if the allergy or the infection was the main driver

What determines the base pruritus in a patient?

The allergy is the predisposition, but the infection is what makes the patient miserable

If a client doesn't understand 'strict' for a food trial, what items might they accidentally give?

Flavored meds, toothpaste, or pill pockets

Which drug is noted for having a very safe profile and excellent client compliance?

Cytopoint (lokivetmab)

What is the single most common missed diagnosis in pruritic patients?

Adequacy/compliance of flea prevention