History:

 Erosive pustular dermatosis is commonly seen on the scalp of severely sun damaged individuals when the scalp is injured either from a graze or after surgery or cryotherapy to the solar damaged skin. 

The best treatment is to use a strong topical steroid cream or lotion BD. It will reform scalp epithelium within 10 days. The pus is inflammatory rather than infective.

See this discussioin of the condition