Dermatology: Dog Pruritis Flashcards

1
Q

An unpleasant sensation of the skin that provokes the urge to scratch is?

A

Pruritus aka Itch

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2
Q

You have an owner come in with the complaint of biting, licking, chewing, scratching gnawing, and/or rubbing. What is top on your differential list?

A

Pruritus

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3
Q

What do we see early on with Pruritus(3)?

A

Alopecia
Erythema
Excoriations

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4
Q

True or False: Depending on the cause, pruritic skin looks the same in most cases.

A

FALSE!

Irrespective of the cause. Location is the key.

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5
Q

What do we see in the Chronic stage of Pruritus?

A

Lichenification
Hyperpigmentation
Seborrhea

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6
Q

True or False: It is important when looking at a pruritic case to look for treatable diseases.

A

True!

You want to find good/treatable diseases when working up the case.

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7
Q

What does it mean to be systematic in your approach with pruritic cases?

A

Determine factors contributing to pruritus.
Diagnostically (Derm pushups) & Treatment
Eliminate factors until diagnosis is obtained
Keep owner informed so they understand each step of the process.

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8
Q

What are the 4 differentials for allergy causes of Pruritus in a dog?

A

Flea allergy
Atopic dermatitis
Cutaneous adverse food reaction
Insect bit hypersensitivity/contact dermatitis

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9
Q

What are the 3 main categories of pruritis in a dog?

A

Allergy
Ectoparasite
Infections

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10
Q

What are the 5 ectoparasites we are worried about with pruritus in a dog?

A
Sarcoptes
Demodex
Cheyletiella
Lice
Chiggers
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11
Q

What is secondary to Demodex in dogs?

A

Pyoderma

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12
Q

What are the 3 infections we are worried about with pruritus in dogs?

A

Staph pyoderma
Yeast
Dermatophytes

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13
Q

You have a dog come in with caudal dorsum pruritus. What is the most likely cause?

A

Flea Allergy

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14
Q

A dog comes in with pruritus on its elbows and ears. What is the most likely cause?

A

Sarcoptic Mange

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15
Q

A dog comes in feet licking and chewing. What is the most likely cause?

A

Atopy or Food Allergy

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16
Q

What does the phrase “rears and ears” refer to?

A

Food Allergy

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17
Q

What two things can be both seasonal and not?

A

Flea Allergy
Atopy
*depends on if multiple allergens or geographic location

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18
Q

What 3 things that cause pruritus in a dog is seasonal?

A

Flea Allergy
Atopy
Insect Allergy

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19
Q

What 6 things that cause pruritus in a dog are not seasonal?

A
Scabies
Food Allergy
Flea Allergy
Atopy
Secondary Infections
Demodex
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20
Q

What is the scale for grading pruritus?

A

Scale of 1-10

Reference point to judge response to treatment

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21
Q

What are the top differentials for a grade 9-10 pruritus?

A

Scabies
Flea Allergy
Food Allergy

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22
Q

What are your top differentials if pruritus came before lesions?

A

Allergies

Scabies

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23
Q

What are your top differentials if lesions came before pruritus?

A

Demodex

Dermatophytes

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24
Q

What are we looking for in a good PE to help narrow down causes of pruritus?

A

Lesions that confirm historical information
Pyoderma, lesion distribution, hair loss, etc
General health
Immunosuppresion
Ear check

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25
Q

What is the most important thing to check when doing a PE of a pruritus patient?

A

Ears!

Often Involved!!!

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26
Q

What is important for you to tell the client when they are going to bring their pet in for pruritus?

A

Do NOT bathe before the visit (for a couple days). You want the organisms to still be there to find.

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27
Q

What are the 5 mainstays of the treatment plan for pruritus patients?

A
Flea control
Treat pyoderma if present
Treat Malassezia infection
Treat Sarcoptes if suspected
Treat ear disease if present
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28
Q

When should you re-assess after treatment for pruritus?

A

1 week… possibly 2 but no later

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29
Q

True or False: Skin disease are usually cured with one visit.

A

FALSE
They are rarely cured with one visit
Many chronic ones are ‘life long’ but controllable

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30
Q

Systemic exposure to allergens occurs when _____ in Flea Allergic Dermatitis.

A

fleas take a blood meal

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31
Q

What type of hypersensitivity is FAD?

A

Type 1 (antigen-antibody reaction)

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32
Q

What signs do you see with FAD?

A

Itching
Inflammation
Excoriations

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33
Q

True or False. Flea Allergic Dermatitis is very common.

A

True!!! Should always be on the list! Use a flea comb every time.

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34
Q

What is it about the flea that causes the hypersensitivity?

A

Saliva!
Contains many antigens, amino acids, aromatic compounds, polypeptides, phosphorus
Sensitizes the Th cell

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35
Q

What is the classical distribution seen on a pruritic dog that has FAD?

A

Lumbo-sacral!

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36
Q

What are the primary and secondary lesions seen in FAD on a dog?

A

P - Papules

S - Crusts

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37
Q

Does FAD show any self inflicted lesions? If so, what are they?

A

Yes!
Excoriations (itching)
Alopecia

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38
Q

What chronic changes do you see with FAD in a dog?

A

Lichenification

Hyperpigmentation

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39
Q

True or False. You will always see fleas with FAD.

A

FALSE.

Fleas or flea dirt may or may not be present. It only takes one!!! Excessive grooming may have removed the fleas.

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40
Q

What is the normal age range for dogs with FAD?

A

1-3 years old

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41
Q

What differential for pruritus usually has the clinical alopecia sign of “pants”?

A

FAD

*Dorsal lumbosacral, tailbase, caudomedial thighs, ventral abdomen, flanks

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42
Q

What two test can you do for FAD? Which is the gold standard?

A

Serum test

Intradermal flea allergy test (Gold standard)

43
Q

What are you looking for with a Serum test for FAD?

A

Flea allergen specific - IgE

44
Q

True or False: A negative result for IgE rules out FAD?

A

FALSE

Can get false negatives

45
Q

Explain what an intradermal flea allergy test is.

A

3 ID injections

  • negative control
  • positive control
  • flea antigen
46
Q

What percentage of skin allergies are flea related?

A

80%

Consider all dermatoses flea related until proved otherwise!

47
Q

What do you treat FAD with?

A

Flea Eradication (on pet and in house/yard)

48
Q

What are the secondary problems associated with FAD?

A

Bacterial pyoderma

Malassezia

49
Q

True or False: You can go ahead and start the pruritic patient on Prednisolone for pruritus while treating for pyoderma.

A

alse

50
Q

What is important to remember about dosing with Prednisolone especially in use of treating pruritus?

A

Reduce by 25% every 7-10 days. Try to decrease to every other day treatment. Give in the early morning.
Need to get to lowest dose that will control signs while rigorously implementing Flea Control.

51
Q

True or False: Client Education is not important in eradicating the source of FAD.

A

FALSE
Estimated 95% of flea eggs, larvae, & pupae live in the environment, not on the pet
Owners need to know to treat all aspects of the environment

52
Q

True or False: You should use Insect Growth Regulator (IGR) ectoparasitic in the environment and adulticides on all in-contacts when treating FAD.

A

True.

Can change to IGR on in-contacts once clinical signs under control

53
Q

Atopy is a hypersensitivity type _____ to _____.

A

Type 1

Aeroallergens

54
Q

What is the lesion distribution for Atopy?

A

Face, ears, ventrum, feet, antebrachium, perineum

55
Q

What is the age of onset (range) of Atopy?

A

4 m to 7 y (most 1-3 years)

56
Q

Other than age and lesion distribution what characterizes Atopy in a dog?

A

Pruritus

Chronic or relapsing (seasonal often)

57
Q

True or False: Secondary infections are common with Atopy or AD.

A

TRUE

58
Q

What secondary infectious are common with Atopy or Allergic dermatitis?

A
Staph pyoderma (68%)
Malassezia
Otitis externa (>50%)
Lick granulomas
*AD is the most common cause of primary otitis!
59
Q

True or False. AD often occurs separately from other allergic or pruritic diseases like FAD, food allergy

A

FALSE

Often occurs concurrently

60
Q

Once AD is diagnosed clinically, what can you do next?

A

Either serum or skin testing is done if owner wishes to use immunotherapy treatment. Results determine which allergens will be used to improve the allergy.

61
Q

Is there a test to confirm Atopy/AD?

A

No!

62
Q

What two tests detect allergen-specific IgE using serum?

A

RAST (radioallergosorbent test)

ELIZA (enzyme linked immunosorbent assay)

63
Q

The 3 tests that detect allergen-specific IgE are?

A

RAST
ELIZA
ID (intradermal skin test)

64
Q

What is the gold standard to test for allergen-specific IgE?

A

ID skin test

65
Q

Anti-pruritic drugs must be stopped ____ before ID testing.

A

Weeks!

Also depends on which drugs as to how long they need to be off of it.

66
Q

True or False. You have to stop using anti-pruritic drugs before ID testing and serum test.

A

FALSE

You do not have to stop using anti-pruritics for serum tests.

67
Q

What are the things that should be avoided before a testing consult with a dermatologist (3)?

A

Avoid oral and topical steroids for at least 1 month before
Avoid antihistamines & essential fatty acids 2 weeks before
No baths for 5 days before

68
Q

What is the positive and negative controls for the ID skin test?

A

Positive - histamine

Negative - saline

69
Q

How do you read the ID test?

A

Grade reactions from 1 (none) to 4 (large) in comparison to controls
Darken room, use light at angle to see reaction & palpate

70
Q

What is the multimodal approach to treat AD?

A
  1. Diagnose & control all infections
  2. Allergen avoidance
  3. Break itch scratch itch cycle (use antihistamines, low dose corticosteroids, cyclosporine, or others)
  4. Allergen-specific immunotherapy (ASIT)
71
Q

What are Dermoscent, Duoxo (duke-so), & Allerderm Spot On?

A

Dermoscent - Linoleic Acid (spot on)
Duoxo - Phytosphingosines (shampoo, spray, spot on)
Allerderm - Ceramides, fatty acids

72
Q

What are the 3 categories of symptomatic relief for AD/Atopy?

A
Weak evidence of efficacy (antihistamines, antidepressants, essential fatty acids, topicals)
Fair evidence (skin lipid therapy)
Strong evidence (glucocorticosteroids, cyclosporine A (Atopica), Oclacitinib (Apoquel), Lokivetmab (CytoPoint), Recombinant k9 interferon gamma (Interdog))
73
Q

Antihistamines have H1 blocking affects, what does that entail?

A

Anti-histamine
Anti-cholinergic
Sedative
Local anesthetic effect

74
Q

What are the side effects of antihistamines?

A

Drowsiness, lethargy, anorexia, vomition, diarrhea, dry eyes/mouth, increased pruritus
Potentiate glaucoma and retentive urinary conditions

75
Q

Name some common antihistamines.

A
Hydroxyzine
Cetirizine
Clemastine
Chlorpheniramine
Diphenhydramine
Dimetindene
Fexofenadine
76
Q

Fatty acids (FA) fit into the weak evidence of efficacy and are important parts of cell membrane _____ _____.

A

Phospholipid layer

77
Q

What are the two Fatty Acids used to treat Atopy?

A

Eicosapentaenoic acid (EPA) & docosahexaenoic acid (DHA)

78
Q

What is used as the “crisis buster” in response to Atopy?

A

Corticosteroids!

Also used as a therapeutic trial if AD is strongly suspected

79
Q

When is best to give prednisolone?

A

In the morning!

80
Q

What are the disadvantages to long term corticosteroids?

A

PU/PD/PP/weight gain
Iatrogenic Cushing’s/Addison’s
Less effective over time = higher doses needed
More susceptible to infections

81
Q

Explain what Cyclosporine A (Atopica) does to the body?

A

T cell inhibitor
Decreases IL-2
Anti-allergic & immunosuppressive

82
Q

What are the side effects of Cyclosporine A (Atopica)?

A

GI, exacerbates skin infection
Gingival hyperplasia, papilloma
Infections, neoplasia

83
Q

True or False. Atopica is best absorbed with food and should be used for at least 4 weeks to see if effective.

A

FALSE
Best absorbed on an empty stomach but if vomiting, give with food.
4 week trial minimum

84
Q

Is it okay to use generics for Cyclosporine A?

A

No. Do not use generic even if cost is a factor.

85
Q

How does Oclacitinib (Apoquel) work?

A

AD triggers cytokine induction triggers Janus Kinase (JAK) enzymes. Apoquel inhibits JAK1 & JAK3 enzymes
Reduces proinflammatory cytokines
Decreases itching and inflammation

86
Q

What are the FDA restrictions on Apoquel for dogs with AD?

A

12 months or older

87
Q

What are the side effects of Apoquel?

A

May increase susceptibility to infection & demodicosis
May exacerbate neoplastic conditions
Avoid using in breeding dogs & pregnant or lactating ones.
*Most common - vomiting, diarrhea

88
Q

What does Lokivetmab (Cytopoint) do in the body?

A

Monoclonal antibody to interleukin (IL)-31

Targets & neutralizes IL-31, a key itch-inducing cytokine

89
Q

What are the side effects of Lokivetmab?

A

Little to no side effects

90
Q

What is the dose protocol for Lokivetmab?

A

1 SQ injection q 4-8 weeks as needed

91
Q

What is Recombinant canine interferon-gamma (IFNy) used to treat?

A

Atopy in Dog!

92
Q

What is the MoA of IFNy?

A

Potent inducer of T helper type 1 immune responses

93
Q

What is the important thing to remember about Recombinant feline interferon-omega?

A

Shown to provide some inconsistent reduction of skin lesions and pruritus in dogs with AD.

94
Q

If you are using Allergen-specific immunotherapy (ASIT) what do you have to do to the allergen over time?

A

Increase dose/frequency of allergen over time.

95
Q

What are the factors effecting clinical efficacy of ASIT or Hyposensitization?

A
Patient Selection ( <10 specific allergens show a better response; eliminate other diseases first)
Allergens (correct ones chosen? Issues with batch?)
Owner Compliance (12-18 months to assess results &amp; maintenance therapy lifetime)
96
Q

True or False. Classic CAFR a separate disease from AD?

A

FALSE.
Food is a trigger for AD just like other triggers. Identical to AD
*challenge to diagnose

97
Q

What are the signs for CAFR?

A
Non-seasonal pruritus
Otitis externa
Secondary Pyoderma
Secondary yeast dermatitis
Possible GI signs
98
Q

What other diseases are CAFR like?

A

Allergic dermatitis
Flea bite allergic dermatitis
Scabies

99
Q

Food allergy is the ____ most common hypersensitivity skin disease.

A

3rd

100
Q

What age group is expected with food allergy?

A

50% <1 year

<6 months, food allergies more common than atopy

101
Q

True or False. GI signs are concurrent with Food Allergies.

A

True. (10-15% of cases)

Vomiting, Diarrhea, Colic

102
Q

Secondary ____ infections are common with Food Allergies.

A

Bacterial/yeast skin infections

103
Q

What is the only way to diagnose food allergy?

A

Positive Response to an elimination diet

  • 95% of dogs improve within 3 weeks
  • biggest limitation is owner compliance
104
Q

True or False: It is important to include no other food sources when doing a food trial.

A

True.
Need strict compliance
Just water and trial diet
And no flavored pills