Samter’s triad includes all, EXCEPT:
**Core Concept**
Samter's triad is a classic association of three conditions that occur together, primarily affecting individuals with aspirin sensitivity. It consists of aspirin-induced asthma, nasal polyps, and sensitivity to non-steroidal anti-inflammatory drugs (NSAIDs).
**Why the Correct Answer is Right**
The triad is caused by a deficiency of cyclooxygenase-1 (COX-1), an enzyme involved in the production of prostaglandins, which are mediators of inflammation. Aspirin and NSAIDs inhibit COX-1, leading to an imbalance between prostaglandin production and the production of leukotrienes, which are pro-inflammatory mediators. This imbalance contributes to the development of asthma, nasal polyps, and sensitivity to NSAIDs.
**Why Each Wrong Option is Incorrect**
**Option A:** Aspirin-induced urticaria is not a component of Samter's triad. Urticaria is a type of skin rash, whereas the triad consists of respiratory and nasal symptoms.
**Option B:** Aspirin-induced rhinitis is indeed a feature of Samter's triad, but it's not the only component. The triad also includes asthma and sensitivity to NSAIDs.
**Option C:** Sensitivity to NSAIDs is a key component of Samter's triad, as these drugs can trigger asthma and rhinitis in individuals with this condition.
**Clinical Pearl / High-Yield Fact**
Individuals with Samter's triad often present with a history of recurrent asthma, nasal polyps, and sensitivity to aspirin or NSAIDs. The diagnosis is often made by excluding other causes of respiratory symptoms and by demonstrating a positive response to a challenge with aspirin or an NSAID.
**Correct Answer: D**