Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Module 7 > Skin & Immune Mediated Diseases 3 > Flashcards

Skin & Immune Mediated Diseases 3 Flashcards

1
Q

what are hypersensitivtity reactions

A

an exaggerated or inappropriate immune response to a mild pathogen or innocuous substance (allergen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is an autoimmune disease

A

a specific humoral or cell-mediated immune response against the constituents of the body’s own tissues (auto-antigens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the types of hypersensitivity reactions

A

type I: anaphylactic, immediate

type II: antibody-dependent, cytotoxic

type III: immune complex mediated

type IV: cell-mediated, delayed

the host reponse to an imagined insult or an over-reaction to a real (but sometimes unidentified or unknown) infectious agent (ex. aberrations of normal immune reactions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is type I hypersensitivity

A

production of antigen specific IgE –> IgE is bound to mast cell membranes

re-exposude to antigen

mast cell degranulation –> release of vasoactive mediators (histamines and prostaglandins) –> severe systemic reaction anaphylaxis or a milder local reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is anaphylaxis/anaphylactic shock

A

immediate systemic reaction caused by rapid IgE-mediated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does anaphylaxis/anaphylactic shock cause

A

immune release of potent mediators from tissue mast cells and peripheral basophils

serious allergic reaction that is rapid in onset and may cause death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does anaphylaxis/anaphylactic shock involve

A

involves skin +/- mucosal tissue; resp. system; gastrointestinal system; reduced BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the process of anaphylaxis/anaphylactic shock

A

release of vasoactive mediators > systemic vasodilation & increased vascular permeability > hypotension & tissue hypoperfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what arre the triggers of anaphylaxis

A

foods

medication

venoms

unidentified

(not all reactions involve IgE –> some triggers directly stimulate mast cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are examples of type I hypersensitivity

A
  1. apopic dermatitis
  2. insect bite hypersensitivity (flea bite)
  3. drug eruptions
  4. food allergy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what accounts for majority of skin disease in dogs and cats

A

atopic dermatitis

flea bite hypersensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what causes atopic dermatitis

A

multifactorial (genetics + environment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a common cause of atopic dermatitis

A

environmental allergens –> commonly house dust mites, insects, pollen, mold, dander of other animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the predisposition of atopic dermatitis

A

seems to be inherited

10% of dogs affected

esp WHWTs, cairns, scotties, boxers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does atopic dermatitis cause and where are common locations

A

pruritic dermatitis and otitis (conjuctivitis)

face, feet, ventrum

itching, red skin, loss of fur, small pus filled or solid bumps in skin, sores that might ooze, recurrent skin and ear infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does atopic dermatitis appear histologically

A

acute inflammation with mast cell rich infiltrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

®how do allergies cause atopic dermatitis

A

allergens can be absorbed via the skin +/- inhaled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what contributes to the pathogenesis of canine atopic dermatitis

A

abnormal skin barrier

  1. variation in filaggrin expression
  2. disorganized lipid lamellae
  3. altered balance of antimicrobial peptides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what research is being done to prevent atopic dermatitis from abnormal skin barrier

A

repair lipid barrier in dogs by topical applications or nutritional supplements

20
Q

what is insect bite hypersensitivity

A

allergic dermatitis –> acute or more often chronic

21
Q

what triggers cause insect bite hypersensitivity

A
  1. fleas
  2. biting midges
  3. black flies
  4. mosquitoes
22
Q

how does insect bite appear on histology

A

focal necrosis beneath surface crust

reaction often characterized by eosinophils

23
Q

what is flea bite hypersensitivity

A

type 1 hypersensitivity (and/or type IV)

common - no breed predilection

may be seasonal –> summer & autumn

24
Q

what does flea bite hypersensitivity

A

pruritic papular dermatitis (miliary eczema)

dorsal lumbosacral area, neck, inner thighs, abdomen

25
Q

what is the features of flea bite hypersensitivity histology

A

may include eosinophils in dermal infiltrate and/or intraepidermal eosinophilic abscesses

26
Q

what is this

A

flea bite hypersensitivity

eosinophil exocytosis, pustules & scale-crust

27
Q

what is this

A

crusted papules & alopecia

28
Q

what is type IV hypersensitivity delayed type hypersensitivity

A

DTH reactions involve same processes as cell-mediated immunity to microbial infection –> not dependent on antibody

balance swings from protection to tissue damage if the stimulus is great or unusually persistent

29
Q

what occurs in type IV hypersensitivity

A

sensitized T-cell population develops after initial contact with antigen via ACPs –> re-exposure –> lymphocyte activation –> cytokine release –> macrophage infiltration

tissue damage is due to activated macrophages and cytotoxic T cells

30
Q

what are delayed hypersensitivity reactions

A
31
Q

what is the tuberculin test

A

an example of DHT

  1. antigen introduced into subcutaneous tissue and processed by local antigen-presenting cells
  2. A TH1 effector cell recognized antigen and release cytokines which act on vascular endothelium
  3. recruitment of T cells, phagocytes, fluid and protein to site of antigen injection causes visible lesion
32
Q

how does DTH reaction cause a granuloma

A

granuloma formation depends on prolonged stimulation (> 2 weeks)

33
Q

what is a disease that causes granulomas

A

tuberculosis

34
Q

what is allergic contact dermatitis

A

type IV hypersensitivity

chemical (hapten) binds to epidermal proteins to form allergen

not commonly diagnosed in animals –> difficult to distinguish from irritant contact

35
Q

what is the appearance of allergic contact dermatitis

A

variably pruritic maculopapular dermatitis –> sparsely haired regions affected especially ventrum –> feet, legs, perineum, scrotum, chin and pinnae

36
Q

what is the histological appearance of allergic contact dermatitis

A

chronic dermatitis with hyperplasia, hypergranulosis, compact hyperkeratosis and lymphocyte exocytosis

37
Q

what is type III hypersensitivity

A

direct damage mediated by antibodies to exposed cell surface antigens –> antigen usually endogenous

binding of antibody (IgG or IgM) +/- complement –> cytolysis or cytotoxicity

38
Q

what causes type II hypersensitivity

A

underlies various autoimmune disorders affecting various tissues –> pemphigus, pemphigoid (epidermal cells), hemolytic anemia (red blood cells)

39
Q

what type of hypersensitivity is sweet itch

A

?

40
Q

what triggers sweet itch

A

culicoides spp. hypersensitivity

41
Q

what are the key features of flea bite hypersensitivity

A

type I hypersensitivity

seasonal –> summer and autumn

pruritic papular dermatitis (miliary excema)

dorsal lumbosacral area, neck, inner thighs, abdomen

histoloy: eosinophils in dermal infiltrate and/or intraepidermal eosinophilic abscesses

42
Q

what type of hypersensitivity is delayed type

A

type IV hypersensitivity

43
Q

name 2 autoimmune conditions which have a hypersensitivity component

A

type II hypersensitivity

pemphigus, pemphigoid (epidermal cells), hemolytic anemia (RBCs)

44
Q

what is shown here

A

allergic contact dermatitis

45
Q

give an example of delayed type hypersensitivity relevant to vet med

A

tuberculosis

46
Q

what is the difference between hypersensitivity reactions and autoimmune disease

A

hypersensitivity: exaggerated or inappropriate immune response to a mild pathogen or innocuous substance (allergen)
autoimmune: a specific humoral or cell-mediated immune response against the constituents of the body’s own tissues (auto-antigens)

Module 7 (50 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions