Image of the Week: Blue-black discoloration on the neck and face

A 58-year-old man with a history of rosacea presents with blue-black discoloration on his neck and face that worsens after sun exposure. What drug is the most likely cause of this reaction?  Learn more about this case, take the quiz, and join the conversation on Figure 1.

 

The Image of the Week for March 11 is brought to you ...