Original
To obtain a diagnosis of AS it is usually done by a Rheumatologist but other doctors could catch if they are familiar with autoimmune disorders. Bloodwork is typically done and there is a gene marker HLA-B27 that is significant for AS and usually hereditary. Just because you have the gene does not mean you have the active disease and you can also have it and not have the market. The Dr also does a physical exam and ask about symptoms and what you have and how long you have been dealing with them. They do Cray usually in the beginning as well especially if SI joints and hands looking for any fusion or damage that may/may not be showing yet. For treatment a Rheumatologist is usually who treats although you still follow with your pcp and sometimes pain management as well and if you have any other areas of concern you would follow that speciality Dr as well.