Atopic Dermatitis Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

An individual with atopy produces what type of antibodies specific to their allergens?

A

IgE

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2
Q

What are non-dermatologic manifestations of atopic disease?

A

asthma, rhinitis, conjunctivitis

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3
Q

True or False: All individuals with atopy (detectable IgE on a serum test) will manifest clinical signs of disease

A

False

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4
Q

True or False: All dogs with clinical atopic dermatitis will have measurable serum IgE against allergens

A

False

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5
Q

True or False: according to the ACVD Task Force definition of atopic dermatitis circa 2006, environmental allergens are the only trigger responsible for atopic dermatitis

A

False (their definition includes food)

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6
Q

What is the name for the disease in dogs with clinical signs of AD but no measurable IgE?

A

Atopic-like dermatitis

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7
Q

What is the name of the hypothesis that decreased exposure to parasites and bacteria, in conjunction with increased practices of bathing and detergents that could harm the skin barrier, are leading to increased incidence of AD?

A

Hygiene hypothesis

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8
Q

exposure to _____ has an inverse relationship with risk of developing AD, supporting the hygiene hypothesis

A

Endotoxin

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9
Q

On which human chromosomes have genes predisposing for atopic dermatitis been found?

A

5, 7, and 11

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10
Q

Two of the strongest factors for AD in humans are loss of function mutations (R501X and 2282der14) on the _______ gene

A

filaggrin

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11
Q

What is the most common name for the human manifestation of atopic dermatitis?

A

Eczema

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12
Q

Impairment of the skin’s ____ function has been documented in both human and canine AD

A

Barrier

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13
Q

In dogs or humans with decreased barrier function, will their TEWL be increased or decreased?

A

increased

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14
Q

Studies have found that atopic beagles have MORE or LESS filaggrin expression than normal controls?

A

less

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15
Q

True or False: Dogs with atopic dermatitis have higher total IgE counts than normal dogs

A

False (allergen-specific IgE, not total)

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16
Q

What subclass of IgG molecules might play an important role in AD?

A

IgGd

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17
Q

Which subtype of IgE is non-pathogenic, IgE+ or IgE-?

A

IgE-

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18
Q

True or False: it is definitively known whether allergen specific IgE development occurs before or after clinical signs of atopic dermatitis

A

False (we know nothing)

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19
Q

Classically, acute AD is associated with a Th2 response and the release of what two cytokines?

A

IL-4 and IL-13

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20
Q

In the biphasic model of atopic dermatitis, chronic lesions are characterized by cytokines of what T-helper profile (1 or 2)? What WBC predominates?

A

Th1 (IL-2, IL-12, IFN-y, IL-18); macrophages

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21
Q

Which chemokines have been associated with AD in dogs and humans?

A

RANTES (CCL5), eotaxin (CCL11), MCP-4 (CCL13), TARC (CCL17), CR4

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22
Q

Transcription/production of which cytokine has been shown to be DECREASED in dogs with AD?

A

TGF-B (one Japanese study also showed IFN-y)

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23
Q

Which cytokine, associated with eosinophil recruitment, has been found in increased levels in dogs with AD?

A

IL-5

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24
Q

Which adhesion molecule has been shown to be up-regulated in lesional skin of dogs with AD?

A

P-selectin

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25
Q

True or False: the role of histamine in canine AD is well-established

A

False (we know nothing)

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26
Q

What neurotransmitter has been shown to be important as a mediator of itch in human AD?

A

Serotonin
(patients treated with Bicarphen, an anti-serotonin drug, have had a good clinical response. Importance in dogs is unknown)

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27
Q

It is suspected that in atopic dermatitis, environmental allergens are epicutaneously captured by _____ cells, which have been shown to be increased in lesional atopic skin

A

Langerhans

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28
Q

Human atopics tend to have an increased number of ____ T cells; in addition to these, atopic dogs tend to have more ____ T cells than their human counterparts

A

Type 2 (alpha-beta); Type 1 (delta-gamma)

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29
Q

previous models of atopic dermatitis emphasized the ____ route of allergen exposure, but recent models and studies have determined the ____ route to be more important

A

Inhalation; Epicutaneous/percutaneous

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30
Q

Atopic dermatitis is typically considered a type ____ hypersensitivity reaction

A

Type I

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31
Q

True or False: clinically, reactions to food allergens may be indistinguishable from reactions to environmental allergens

A

True

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32
Q

Which environmental allergens have been shown to induce signs of AD when ingested?

A

Dust (and storage) mites

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33
Q

True or False: as in humans, self-antigens have been clearly demonstrated to play an important role in canine atopic dermatitis

A

False (self IgE antibodies not found in canine studies)

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34
Q

True or False: A direct association has been established between S. aureus superantigens and the development of human AD

A

True

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35
Q

This genus of bacteria is over-represented in colonization of and adherence to atopic canine skin

A

Staphylococcus (pseudintermedius)

36
Q

True or False: S pseudintermedius can act as an allergen in some dogs, eliciting its own IgE response

A

True

37
Q

What are the most common body sites to find malassezia on an atopic dog?

A
Interdigital spaces (70.7%), Ears (63.4%), 
Less common: nail folds (35.7%), mouth (33.3%), groin (30.9%), conjunctiva and axillae (23.8%)
38
Q

True or False: Malassezia antigens have been demonstrated to elicit a hypersensitivity response in atopic dogs

A

True

39
Q

True or False: Atopic dogs with malassezia overgrowth are more likely to test positive for reaction to Malassezia antigens on skin test and serum testing than those without malassezia overgrowth

A

False (true for skin test but not for serum)

40
Q

True or False: Puppies born during high pollen season are at higher risk of developing AD

A

True (according to one study cited by SAD; we probably don’t really know lol)

41
Q

Allergen avoidance during ____ life may have a preventive effect on IgE-mediated allergy in dogs

A

Early

42
Q

Which of the following factors has an effect on risk of developing AD?
A) Age
B) Gender
C) Vaccination status

A

A) Age. Age of exposure affects risk (younger exposure increases risk), Study quoted in SAD said deworming status also had NO effect on risk, which would contradict hygiene hypothesis (do we know anything?)

43
Q

While AD is typically thought of as developing between 6 months and 3 years of age, Small Animal derm says it can develop as soon as ___ months and as late as ____ years

A

4 months; 7 years

44
Q

What is the most common reason for an older dog (>3 years) to develop AD?

A

Geographic move

45
Q

What primary skin lesions are seen with canine Atopic Dermatitis?

A

TRICK QUESTION! THERE ARE NONE! (Pruritus sine material) Arguably erythema; macules and papules are controversial, often due to secondary infection or self-trauma

46
Q

What non-skin signs can be present in dogs with atopic dermatitis?

A

conjunctivitis, otitis, hyperhidrosis, rhinitis, reverse sneezing, GI signs in food allergy

47
Q

Name 3 of Willemse’s major criteria for AD

A

Pruritus, facial/digital involvement, lichenification of tarsi/carpi, chronic/relapsing dermatitis, family history, breed predisposition

48
Q

Name 3 of Willemse’s minor criteria for AD

A

Onset before 3y, facial erythema and chelitis, conjunctivitis, staph pyoderma, hyperhidrosis, skin test reactivity, elevated allergen-specific IgE and IgGd

49
Q

What are Favrot’s criteria for AD?

A

Onset before 3y, glucocorticoid-responsive pruritus, affected front feet, affected ear pinnae, chelitis

50
Q

True or False: Regardless of whether an owner wants to do immunotherapy, allergy testing is a valuable test because it helps us determine whether a pet is allergic or not

A

False

51
Q

True or False: Including false-positive results in an immunotherapy mix runs the risk of sensitizing the dog to antigens it was not allergic to

A

False? (per SAD, a study in normal dogs showed no effect of irrelevant allergens on skin test results or clinical signs, but do we really know)? Allergy textbook may have a different answer

52
Q

Which of the following is NOT a reason for a false-negative IDT result?
A) Drugs (glucocorticoids, antihistamines)
B) Outdated antigens
C) Off-season testing
D) Estrus
E) All of the above are valid reasons

A

E

53
Q
Which of the following is NOT a reason for a false-positive IDT result?
A) Irritant allergens
B) Contaminated antigens
C) Dermatographism
D) pseudopregnancy
E) All of the above are valid reasons
A

D (this is actually a reason for a false negative)

54
Q

What insects have been shown to cross-react with dust mites in human allergy testing?

A

Cockroaches

55
Q

What is the most common/important allergen in dogs in Europe, Japan, and the United States

A

House dust mite

56
Q

True or False: a positive reaction to histamine ensures that the dog being tested will not have false negative reactions on its skin test

A

False

57
Q

The only antihistamine that has been evaluated in dogs for effects on skin testing reactivity is _____.

A

Hydroxyzine

58
Q
Which of the following sedatives will NOT affect skin reactivity for IDST?
A) Acepromazine
B) Ketamine/diazepam
C) Telazol
D) Propofol
A

C (weird that Ket-val does and Telazol doesn’t)

59
Q

What are the 3 most common serologic allergy tests in use?

A

RAST, ELISA, liquid-phase immuno-ezymatic assay

60
Q

Which of the following is NOT an advantage of serum allergy testing over skin testing?
A) Lower risk (sedation, anaphylaxis)
B) Convenience/aesthetics (no clipping)
C) Increased sensitivity/specificity
D) Less affected by prior drug use
E) Can be performed in dogs with active dermatitis lesions on the skin

A

C

61
Q

What are the typical histopathologic findings of atopic dermatitis?

A

Spongiotic dermatitis with eosinophilic exocytosis
(acute), Superficial perivascular dermatitis with lymphocytic exocytosis, higher numbers of neutrophils in late-phase reactions

62
Q

True or False: Pruritic threshold and threshold of atopic disease are the same thing

A

False. Many things can make a dog itchy that aren’t allergies

63
Q

True or False: Allergen avoidance is the most important part of multimodal therapy for environmental allergies

A

False

64
Q
Which of the following is NOT a benefit of topical therapy in treatment of AD?
A) Allergen removal
B) Raises the pruritic threshold
C) Infection control
D) Sparing effect for systemic drugs
E) Improve barrier function
A

B

65
Q

True or False: Topical glucocorticoids are safer than systemic glucorticoids and can be used daily without any adverse effects

A

False

66
Q

Which topical calcineurin inhibitor can be used in place of topical glucocorticoids in pruritic patients with cutaneous atrophy?

A

Tacrolimus

67
Q

True or False: No published data exists to prove the efficacy of phytosphingosine for barrier enhancement and infection prevention

A

True (as of 2013)

68
Q

An open study in dogs with chronic AD showed clinical improvement within ___ weeks of commencing topical therapy with ceramides

A

6

69
Q

True or False: The exact mechanisms of ASIT are unknown

A

True

70
Q

Classically, ASIT was thought to drive the T-helper immune response from a ____ to ____ profile, but recent studies have also emphasized the importance of the induction of ____ cells

A

Th2; Th1; Treg

71
Q

Which of the following has been shown to affect the success of ASIT?
A) Adjusting protocol to patient response
B) Serum vs skin testing
C) Type or number of antigens included in vial
D) Age of dog when disease developed

A

A

72
Q

In general, owners should be asked to continue ASIT for ____ before assessing the full benefits of the therapy

A

1 year

73
Q

____ breeds appear to be prone to more adverse effects from ASIT when large doses are given

A

Toy breeds

74
Q

In what time period are adverse (anaphylactic) reactions to ASIT most likely to be observed?

A

the first 30-60 minutes after an injection (pruritus can be 1 to 2 days later)

75
Q
Which of the following is NOT a reportable adverse reaction to ASIT?
A) hives
B) facial swelling
C) seizures
D) vomiting/diarrhea
A

C

76
Q

If adverse reactions to ASIT injections are seen, what is the most appropriate next step to take?
A) decrease dose
B) premedicate with antihistamines
C) both/either of above

A

C

77
Q

What is the benefit of Rush Immunotherapy?

A

Decreases the time necessary to achieve maintenance doses

78
Q

What are the 3 forms of allergens that can be used in ASIT, ranked from fastest to slowest speed of absorption?

A
  1. Aqueous
  2. Alum-precipitated
  3. Emulsion
79
Q

True or False: Allergen Specific Immunotherapy has a higher rate of success than regional-specific immunotherapy

A

True (70% vs 18% success according to SAD)

80
Q

Which of the following is the least important for maximizing success of ASIT?
A) client education
B) close monitoring of patient response
C) adjusting protocol to patient response
D) beginning with a skin test as opposed to serology

A

D

81
Q

True or False: Anti-IgE vaccines have been shown to be just as effective as ASIT in reducing clinical signs of AD in dogs

A

False

82
Q

Name a phospodiesterase inhibitor that has been shown to have some beneficial effects in dogs with AD

A

Pentoxifylline

83
Q

The distribution of AD lesions in cats is thought to be correlated to the presence of mast cells in the skin. What two areas in cats have the highest concentration of mast cells?

A

caudal pinnae and the chin

84
Q

More than 80% of atopic cats have detectable serum IgE against ______

A

D. farinae (also most common environmental allergen in dogs)

85
Q

What are the 3 clinical presentations of EGC in cats?

A

Plaque, granuloma, ulcer