Can you identify these painful nodules in this boy's leg?

(Case and image courtesy of Shannon Etheridge Whitten, MS, NP-C)
 
Clues:
. Nonpruritic nonsuppurative painful erythematous nodules on the lower extremities of a 5–year-old boy. 
 

. The rash appeared about 1 week after the onset of a dry hacking cough.

. The child had a low-grade fever and joint pain, as well as effusions in his right knee and elbow.
 
Hints:Erythema multiforme MRSA Erythema nodosum Insect bite What’s your diagnosis?