<<Disclaimer: Verify this information before applying it to your situation.>> I would recommend that your brother visit a local dermatologist. The diagnosis of DH could be based upon clinical presentation confirmed by immunofluorescent studies of a punch biopsy of the skin. The immunopathological studies of the biopsy of the skin are the hallmark of DH. These biopsies could be sent to any other specialized laboratory. Any questions? Vijay Kumar, Ph.D., FACB