Crusty Scalp Lesion

November 20, 2015

An 89-year-old woman is seen for an erosion on the frontal area of the scalp. History is positive for actinic keratosis. What's your Dx?

An 89-year-old woman with a history of biopsy-proven actinic keratosis on her scalp is seen for a new erosion on the right frontal area. Two weeks of twice-daily mupirocin has brought no improvement and now crusting and purulent exudate are seen. Skin cultures taken show normal flora.

 

What is your diagnosis?