Immunology Review Corner

Prepared by John Norvell, M.D., Vanderbilt University; Karla Lowe, M.D., Walter Reed Medical Center; and Michael Rupp, M.D., University of Mississippi.

Chapter 38: In vivo Methods for Study of Allergy

1. The release of histamine and tryptase as a result of skin testing peaks at:
a. 5 minutes
b. 30 minutes
c. 60 minutes
d. 90 minutes

2. Which of the following enhances the release of histamine by mast cells?
a. Substance P
b. Neurokinin A
c. CGRP (calcitonin gene-related peptide)
d. Tryptase

3. Which of the following are important precautions to take before applying an allergen skin test?
a. Never perform skin tests unless an BLS certified healthcare professional is present
b. Always use bacteriostatic saline as a control to prevent possible infections
c. Be certain that test concentrations are appropriate
d. Have epinephrine present in the exam room

4. Common errors in intradermal skin testing include:
a. Air injection leading to a false-negative bleb
b. Use of topical anesthetic cream, reducing the wheal response
c. Volume injected is too small, <0.5 ml
d. Subcutaneous injection leading to false-negative test

5. With the use of standardized and potent extracts, prick-puncture testing has which of the following advantages over intradermal testing?
a. Prick-puncture testing is more sensitive than intradermal testing
b. Prick-puncture testing is more reproducible than intradermal testing
c. Prick-puncture testing is more specific than intradermal testing
d. Prick-puncture testing has fewer false-negatives than intradermal testing

6. Record the reactions to skin testing at:
a. 30 minutes for allergens, positive control, and negative control
b. 10 minutes for allergens
c. 10 minutes for histamine control
d. 20 minutes for histamine control

7. Which of the following areas of the body is the most reactive in regards to skin testing?
a. Wrist
b. Antecubital fossa
c. Upper back
d. Lower back

8. Most infants have a significantly detectable wheal with prick-puncture testing at:
a. 1 month
b. 2 months
c. 3 months
d. 6 months


9. Which of the following medications increases skin test reactivity?
a. Lisinopril
b. Clonidine
c. Dopamine
d. Nifedipine

10. Which of the following is a cause for false-negatives on skin testing?
a. Disease attenuating the skin response, e.g., chronic renal failure
b. Decreased reactivity of the skin in adolescents
c. Circadian rhythms
d. Use of inhaled corticosteroids

Answers
1. b, page 631
2. a, page 631
3. c and d, page 632
4. d, page 633
5. c, page 634
6. c, page 634
7. c, page 635
8. c, page 636
9. a, page 637
10. a, page 638