Which type of hypersensitivity reaction is the patient with a poison ivy skin rash experiencing

(M1.IM.17.4767) A mother brings her 6-year-old son to the pediatrician with a 7 week history of cough and shortness of breath. The mother says that his cough is dry and worse at night when it sometimes wakes him up from sleep. The cough has not been associated with a fever and growth charts reveal that he is growing well. Past history is significant only for travel to many countries on vacation over the last few years. Physical exam reveals end expiratory wheezing and the finding shown in Figure A. The most likely cause of this patient’s symptoms is an example of which of the following types of disorders?

QID: 109089

FIGURES:

• A

Type & Select Correct Answer

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1

Type I hypersensitivity

53%

(126/236)

2

Type II cytotoxic hypersensitivity

9%

(22/236)

3

Type II non-cytotoxic hypersensitivity

8%

(18/236)

4

Type III hypersensitivity

11%

(25/236)

5

Type IV hypersensitivity

17%

(39/236)

(M1.IM.14.61) You are working in the emergency room of a children's hospital when a 4-year-old girl is brought in by ambulance due to "difficulty breathing." The patient had been eating lunch on a school field trip when she suddenly complained of abdominal pain. Shortly thereafter, she was noted to have swelling of the lips, a rapidly developing red rash and difficulty breathing. In the ambulance her blood pressure was persistently 80/50 mmHg despite intramuscular epinephrine. In the course of stabilization and work up of the patient, you note an elevated tryptase level. What is the mechanism behind this elevated tryptase level?

QID: 100864

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1

IgG production by plasma cells

1%

(1/159)

2

IgM mediated complement activation

4%

(6/159)

3

Cross-linking of IgE on mast cells

87%

(139/159)

4

Antibody-antigen immune complexes

4%

(6/159)

5

Cross-linking of IgG on mast cells

3%

(4/159)

(M1.IM.14.60) A 5-year-old African American female has experienced recurrent respiratory infections. To determine how well her cell-mediated immunity is performing, a Candida skin injection is administered. After 48 hours, there is no evidence of induration at the injection site. Of the following cell types, which one would have mediated the reaction?

QID: 100481

Type & Select Correct Answer

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1

Plasma cells

6%

(8/135)

2

Basophils

2%

(3/135)

3

T-cells

75%

(101/135)

4

Mast cells

13%

(18/135)

5

Fibroblasts

1%

(1/135)

(M1.IM.14.1) While playing in the woods with friends, a 14-year-old African-American male is bitten by an insect. Minutes later he notices swelling and redness at the site of the insect bite. Which substance has directly led to the wheal formation?

QID: 100422

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1

IFN-gamma

4%

(6/144)

2

Histamine

87%

(125/144)

3

IL-22

0%

(0/144)

4

Arachidonic acid

3%

(4/144)

5

IL-4

6%

(8/144)

(M1.IM.14.1) A 32-year-old female presents with a three month history of oral ulcerations and blisters throughout her body. When the physician examined the skin, she noted that when the skin was rubbed it sloughed off and formed blisters within a few minutes. A skin biopsy was performed and analyzed via immunofluorescence using anti-IgG antibodies (Figure A). Which of the following antibodies is also involved or found in a similar type of hypersensitivity reaction as in the case mentioned?

QID: 106310

FIGURES:

• A

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1

IgE against the proteins in apitoxin

4%

(6/134)

2

Anti-glomerular basement membrane

65%

(87/134)

3

Anti-dsDNA

12%

(16/134)

4

IgE against pollen

7%

(10/134)

5

Anti-Smith

7%

(9/134)

(M1.IM.14.29) A 28-year-old female suffering from a urinary tract infection is given trimethoprim-sulfamethoxazole (TMP-SMX) by her physician. Several days later, she begins to experience itchiness and joint pain. Laboratory and histologic analysis reveals vasculitis and antibody complexes deposited near the basement membrane of the glomerulus. What other serological finding is expected with this presentation?

QID: 100450

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1

Decreased levels of IgE

0%

(1/200)

2

Increased levels of IgE

12%

(24/200)

3

Decreased neutrophil count

4%

(8/200)

4

Increased serum levels of complement protein C3

29%

(58/200)

5

Lowered serum levels of complement protein C3

52%

(105/200)

(M1.IM.13.50) While hunting, a 45-year-old Caucasian man is stung by a bee. He begins to feel unwell and is taken to the hospital. Upon arrival, it is noted that the patient is hypotensive with a blood pressure of 60/40 mmHg. Furthermore, the patient is tachycardic and edematous. What is responsible for this patient's presentation?

QID: 100471

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1

Free IgE binding to the antigen

3%

(9/335)

2

IgE, on mast cell surfaces, binding to the antigen

83%

(279/335)

3

IgE activation of complement

7%

(23/335)

4

Complexes of IgE binding to the antigen

1%

(3/335)

5

IgE, on eosinophils, binding to the antigen

5%

(17/335)

(M1.IM.13.37) A 30-year-old Caucasian male presents with hemoptysis and uremia. Blood tests show the presence of anti-basement membrane antibodies specific for collagen located in glomerular and pulmonary basement membranes. The patient undergoes plasmapheresis to help reduce the amount of anti-basement membrane antibodies. Which of the following diseases is of the same hypersensitivity category as this disease?

QID: 100458

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1

Myasthenia gravis

66%

(131/200)

2

Systemic lupus erythematosus

25%

(50/200)

3

A PPD test

4%

(9/200)

4

Seasonal allergies

1%

(2/200)

5

Poison ivy rash

2%

(5/200)

(M1.IM.13.4) A 32-year-old pregnant woman (para 2) presents to the clinic for a routine ultrasound; Figure A displays the ultrasound findings. The fetus has become anemic and levels of unconjugated bilirubin have increased dramatically. Which type of hypersensitivity reaction has occurred and what is mediating the disease state?

QID: 100425

FIGURES:

• A

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1

Type I hypersensitivity; antibody-mediated opsonization

5%

(17/338)

2

Type II hypersensitivity; antibody-mediated opsonization

70%

(238/338)

3

Type II hypersensivity; cell killing via cytotoxic T cells

14%

(47/338)

4

Type III hypersensitivity; cell killing via cytotoxic T cells

6%

(19/338)

5

Type IV hypersensitivity; cell killing via NK cells

3%

(9/338)