An 18-Year-Old Man Is Evaluated for Recurrent Episodes of Shortness

question 423

Multiple Choice

An 18-year-old man is evaluated for recurrent episodes of shortness of breath, wheezing, runny nose, and watery eyes.  The patient reports that his symptoms have recently worsened since he started training outdoors for an upcoming marathon.  He does not use tobacco, alcohol, or illicit drugs.  Skin testing is performed to determine symptom triggers.  A pricking device is used to apply allergen extract underneath the skin.  After 15 minutes, the patient develops raised, erythematous plaques with surrounding erythema at the application site.  Which of the following mediators is the first to be released during the pathogenesis of this patient's skin findings?

• A)Histamine
• B)Leukotriene D4
• C)Major basic proteins
• D)Platelet-activating factor
• E)Prostaglandin D2