“…Equally important is careful exclusion of differential diagnosis such as other causes of arthritis of viral, bacterial, arthropod-borne etiology, reactive arthritis, gout and chronic arthritis. 33 In absence of conclusive diagnosis, presence of surrogate findings such as reactive immunologic reactions, arthritis and erythema nodosum, may be suspected for tubercular infection as respiratory symptoms may be absent at presentation or may follow later. 34 In a case, presence of erythema nodosum and polyarthritis with mediastinal widening due to lymphadenopathy on CT was later diagnosed as PD.…”