A patient brought in to the ER is barely breathing. A new intern takes one look at the patient and diagnoses him with alcohol intoxication. You, however, observe track marks along the patient’s arm....

A patient brought in to the ER is barely breathing. A new intern takes one look at the patient and diagnoses him with alcohol intoxication. You, however, observe track marks along the patient’s arm. What alternative diagnosis is possible? Why is it important to distinguish between the two?