Dyspnea following intravenous drug use

A 41-year-old man was referred to the outpatient clinic of our respiratory care department presenting with the symptoms of progressive cough, exertional dyspnea and tachycardia. The symptoms had started about 18 months earlier and had worsened continuously during the past year. At presentation the patient complained of dyspnea at the slightest exertion. An external chest radiograph showed shadowing with a bilateral perihilar “butterfly” distribution consistent with sarcoidosis and silicosis. The medical history revealed a history of intravenous drug abuse with cocaine for a period of three years until twelve years before presentation. The patient continued to smoke cigarettes (cumulatively 40 pack years) and to use methamphetamines and cannabis. The patient has been suffering from bronchial asthma and