In a child with sudden progressive dyspnea, eosinophilia, and Charcot-Leyden crystals, which mediator is primarily involved in the pathogenesis of asthma?

• A. Histamine
• B. Acetylcholine
• C. Leukotrienes
• D. Prostaglandin E2

Answer: (C)

In asthma with eosinophilic inflammation, the key players are leukotrienes released by eosinophils and other inflammatory cells. Leukotrienes such as LTC4, LTD4, and LTE4 are powerful bronchoconstrictors that also promote mucus production and airway edema, driving the sustained airway narrowing that leads to progressive dyspnea. The presence of eosinophilia and Charcot-Leyden crystals supports this eosinophil-driven inflammatory pathway, making leukotrienes the primary mediators in the pathogenesis here.

Histamine mediates mainly the immediate, early-phase bronchoconstriction but is not the principal driver of the ongoing airway hyperreactivity in this eosinophilic pattern. Acetylcholine causes bronchoconstriction via the parasympathetic system but isn’t the central inflammatory mediator in asthma. Prostaglandin E2 has variable roles and is not the main driver in this eosinophil-rich scenario.