It could be anxiety or medication-induced. My son will not wear anything but soft, tagless clothes, athletic wear. I think it started around age 6 or 7. I think this is when they are able to make the association between the feeling and their clothes and start to voice that it’s uncomfortable. Talk to his clinician about this.
ADDitude Community Moderator, Parenting ADHD Coach & Author, Mom to teen w/ ADHD, LDs, and autism