system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 23-year-old man comes to the physician because of a 1-year history of episodic shortness of breath. Physical examination shows no abnormalities. Laboratory studies show elevated serum IgE levels. Microscopic examination of the sputum shows eosinophilic, hexagonal, double-pointed crystals. A methacholine challenge test is positive. Exposure to which of the following is most likely responsible for this patient's condition?
assistant
Dust mites