Review Question - QID 210596

A 82-year-old man who is currently being managed by the internal medicine service agrees to be examined by medical students as part of their training in physical examination. He is visited by a small group of medical students under the instruction of a preceptor and allows the students to make observations. They find that he has bibasilar crackles that are most prominent during inspiration as well as some wheezing. Furthermore, he coughs up some sputum during the exam, and this sputum is found to have a rust color. He does not report any pain and no skin findings are seen. Which of the following is most closely associated with the cause of this patient's physical exam findings?