Prince Erik had epilepsy and mild intellectual disability. His exact condition has not been published, but he may have suffered an injury at birth. He was described as handsome and physically healthy. His mental disability was not noticeable in brief conversation, but would become apparent if he was engaged at length.
Because of his condition, he was seldom seen in public and led a quiet life away from the public eye, similar to the life of Prince John of the United Kingdom. Because he was a member of the royal family, he was present in official royal photographs, but he had no official tasks. In 1907-1909, a residence was built for him away from the public eye in Djursholm, a relatively new garden community north of Stockholm.
Erik was cared for by many members of the same staff that were responsible for him and his brothers when they were children: Louise Rinman, referred to by the siblings as Vass, was responsible for the upbringing of him and his siblings when they were little, and in the case of Erik, she continued to be so until his death Every two weeks, he was allowed a trip to the capital, during which he sometimes could be seen visiting the opera, and these were the only times he was seen in public except for official photographs.
In 1917, he complained about having to live in such isolation, and it was decided that he should have a new residence closer to Stockholm. However, he died the next year of the Spanish flu at Drottningholm Palace. His parents were not present when he died which, according to official memoirs, caused his father great sorrow in later years. His mother, who herself had poor health and spent parts of the year in Italy, was abroad at the time. Reportedly his brothers felt sorry for him.
His former residence on Germaniavägen in Djursholm has been in private ownership since the 1960s and today (2011) is the private residence of South Africa's ambassador to Sweden.
* prince through adoption or election
** also prince of Norway
^lost his title due to an unequal marriage
#also prince of Poland and Lithuania
~Prince of Sweden by birth and marriage
*** Prince of Sweden by marriage only