A 34-year-old woman with asthma and recurrent nasal polyps develops severe bronchospasm within an hour of taking ibuprofen. The mechanism responsible is:

• A IgE-mediated mast cell degranulation triggered by the drug hapten
• B COX-1 inhibition shunting arachidonic acid toward excess cysteinyl leukotriene production ✓
• C Direct histamine release from basophils by the pyrazole ring structure
• D Complement activation through the classical pathway

Explanation

This is aspirin-exacerbated respiratory disease (Samter's triad: asthma, nasal polyposis, and NSAID reactions). Inhibition of COX-1 diverts arachidonic acid down the 5-lipoxygenase pathway, producing a surge of cysteinyl leukotrienes that provoke bronchoconstriction. It is a pharmacologic, pseudoallergic reaction, so IgE testing is negative and selective COX-2 inhibitors are usually tolerated.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.