&chief_complaint=Low Back pain and stiffness with pain and swelling of involved joints and a skin rash

&phys_exam=Tenderness unilateral Sacroiliac joint and swelling and tenderness of involved peripheral joints

&cor_dif=Psoriatic Arthritis,Reactive Arthritis,

&incor_dif=Rheumatoid Arthritis,Systemic Lupus,

&review=presentation and differential diagnosis of Spondyloarthropathy