Yes, it's a real word
Lookups for affluenza spiked on April 13, following the news that Ethan Couch, the teenager who used a so-called affluenza defense after killing four people while driving drunk, has been sentenced to nearly two years in jail. Couch first made headlines in 2013 when his defense attorney suggested that the privileged circumstances of his upbringing resulted in an inability to distinguish between right and wrong.
Affluenza is defined in Merriam-Webster’s Unabridged as “the unhealthy and unwelcome psychological and social effects of affluence regarded especially as a widespread societal problem.” The word was not coined at Couch’s trial; it has been in English use throughout much of the 20th century. Initially it was employed in a jocular fashion, as in an article from the Houston Post in 1918:
“It is not the sneezing of the Spanish influenza that Liberty needs, but a little more ‘coughing’ on the part of American affluenza.”
By the 1970s the word came to be used more specifically in the sense defined above.
Affluenza is a portmanteau, a blend of affluent and influenza: two words with Latin origins. Affluent comes from a word meaning "flowing with, abundant." The origin of influenza, from the word for "influence," reflects the ancient belief that epidemics were influenced by the stars.