joint case

Joint case

A 16-year-old boy injures his lower left thigh during a high school football game. The pain associated with this injury is so intense that he has to leave the game. The pain subsides for several hours but returns during the night, and the boy develops chills followed by a fever of 39.5ºC. A physician examines him the next morning and notices that the lower left thigh is hot, swollen, and tender. The knee joint appears normal and has a full range of motion. The patient has a temperature 38.3ºC. The physician notes several small boils on the boy’s neck and chest. Some of these are scarred and crusted, and the patient admits that he has been squeezing them during the past few days. X-rays of the left femur indicate soft tissue swelling without any obvious abnormalities of the bone.

Question 1.1: What is your diagnosis?

Question 1.2: How would you handle this case?

Question 1.3: What is the probable causative agent?

Question 1.4: How did the patient’s bone become infected?

Question 1.5: What is the correct treatment for this disease?

Question 1.6: What is the prognosis?

Question 1.7: What can happen if this disease is mistreated or misdiagnosed?


Five days after the onset of her most recent menstrual cycle, a 24-year-old woman begins to experience fever and chills. Soon thereafter, many of her joints become painful, including those in her knees, elbows, wrists, ankles, hands, and feet. These symptoms persist over the next 24 hours, during which a small number of reddish sores (papules) appear on several fingers and the palms of her hands. By the time she gets to a physician (the next day), some of the papules have developed into painful, hemorrhagic pustules. Her vital signs are T = 38.5 C, P = 80, R = 16, BP = 130/70 mm Hg. On physical examination, it is noted that the pustules on her extremities are surrounded by a distinct red areola and that a few papules have also developed on her trunk. Except for the apparently inflamed joints, there are no other remarkable findings. On taking the patient’s history, the physician finds that she has been sexually active with multiple partners but has not experienced any noticeable signs or symptoms typical of common STDs. She uses birth control pills; most of her partners don’t bother with condoms.

Question 2.1: What is your preliminary diagnosis?

Question 2.2: What tests should you perform?

Question 2.3: Are the negative culture results consistent with the diagnosis?

Question 2.4: How did this infection get started?

Question 2.5: What is the prevalence of this disease?

Question 2.6: Is this the only type of joint disease associated with this agent?

Question 2.7: How should you treat this?


A 27-year-old sexually active male who does not use condoms presents with dysuria, especially at the beginning of urine flow, and a purulent discharge from his penis. A diagnosis of gonorrhea is made and later confirmed by the laboratory, so he is treated with a single dose of Ciprofloxacin (500 mg, PO), followed by doxycycline (100 mg, PO, bid) for 7 days. The treatment is successful and the man’s symptoms disappear within 3 days.

Several weeks after the above incident, the man begins to experience painful, asymmetric polyarthritis in his right knee, ankle, and foot. He also notices the appearance of mucocutaneous lesions in his mouth. The arthritis persists over the next several days and is joined by some lower back pain. At this point, he develops a very noticeable conjunctivitis, begins to worry, and finally seeks medical help. His vital signs are normal. On physical examination, there are no remarkable findings in addition to those already described. Specimens of synovial fluid are obtained and sent to the laboratory for culturing, but the results are negative. X-rays of the affected joints are not overly instructive.

Question 3.1: What is your diagnosis?

Question 3.2: What is the differential?

Question 3.3: What is the most likely causative agent?

Question 3.4: How does this condition come about?

Question 3.5: Can anything else lead to this syndrome?

Question 3.6: How can you treat this problem?

Joint case A 16-year-old boy injures his lower left thigh during a high school football game. The pain associated with this injury is so intense that he has to leave the game. The pain subsides