Enthesitis also occurs in about 10% to 20% of children with juvenile idiopathic arthritis, which can affect one or more joints and lasts at least six weeks. These children are described as having enthesitis-related arthritis (ERA). Kids with ERA often have a family history of inflammatory conditions, like ankylosing spondylitis, psoriatic arthritis, or inflammatory bowel disease. They also commonly have eye redness and pain, along with other arthritis symptoms.