A 27-year-old female presents with chills, high fever, and profuse sweating for one week on September 20. The fever pattern was irregular. Malaria parasites were found on blood smear, and she was treated with chloroquine plus primaquine. Fever subsided after 2 days but recurred abruptly on day 4 with low back pain and dark brown urine. What signs should be specifically checked during physical examination at this stage?