Azariah was 16 years old (!) when he became king of Judah. Today's text states that 'he did right in the eyes of the Lord' but failed on one important front. It seems he allowed the 'high places,' those places where other gods would be worshiped, to remain in place. As a consequence, the Lord caused him to be leprous until the day he died, living separately and having his son administrate his kingdom.
Many of the kings of Israel and Judah failed because their reigns and their lives were characterized by the 'sins of Jeroboam.' Jeroboam, king of Israel, reigned as the nation was first divided. And, because the Temple was outside his kingdom, he was fearful that as the people made their pilgrimage to Jerusalem their hearts would return to the king of Judah. So he built places for them to worship and sacrifice within the borders of his kingdom. They no longer would need to, or be allowed to, travel to the Temple to worship. His fear led to increased and encouraged idolatry and it brought the wrath Lord.
Idolatry is nothing new and is something that should cause concern. Idolatry is even the focus of today's New Testament reading as the Ephesians were rioting because so many were turning to the Lord and away from Artemis, their local deity. Here is a warning in the form of a question: what do you love more than the Lord? Do not allow idolatry to take root in your heart or your surroundings. The punishment to Azariah was leprosy...a deadening of the nerves so you cannot feel. And a 'failure to feel' will lead to all sorts of bad decisions, devastated relationships and missed opportunities.