Sarcoidosis

This is a pattern-recognition question.  If you take away the patterned aspect of this Q, you end up with a laundry list of ddxes: everything from infectious (deep fungal, AFB, bacterial, parasitic, viral) to neoplastic (weird CTCLs, etc.) to factitial (excoriated bug bites, etc) to inflammatory.  This is, of course, a special kind of inflammatory condition, and one that is all too common in African Americans.

From now on, for the rest of your natural lives, please remember this:  Any weird rash on African Americans can be sarcoidosis, and the importance of this point is this:  In many cases the skin manifestations of sarcoidosis precedes the other symptoms, and as such is the bellwether for the disease.  The worse the skin disease, the worse the systemic sarcoidosis.  And since we are often tempted to treat inflammatory skin diseases empirically, we can miss an important cutaneous manifestation of a systemic disease.  Given that sarcoidosis can irreversibly damage kidneys, eyes, lungs and liver, it is well worth recognizing the possibility and diagnosing it before the cat, so to speak, gets out of the bag.

Sarcoidosis, like syphilis, is a great imitator.  It can look like many different diseases (see the first paragraph above) and can cause great harm, like lues, if left unrecognized. 

Sarcoidosis is more common in the African American community at large (three times as common as the general population) and is more severe than in Caucasians.  So, in the future, if I throw up an image, and it is from an African American, and you can't tell exactly what it is, your answer should be "sarcoidosis until proven otherwise".