A 22-year-old woman comes to the emergency department because of pain and swelling in her left knee for the past three days. She denies fever, chills, skin rash, or dysuria. However, she reports a one-week episode of diarrhea one month ago. Stool cultures at that time were positive for Shigella flexneri, and the physician at the student health center prescribed ciprofloxacin for three days. She has no other past medical history and her last menstrual period was one week ago. She is sexually active with her new boyfriend.
Her temperature is 37.2 C (99 F), blood pressure is 117/68 mm Hg, and pulse is 87/min. On physical examination, her left knee is tender to palpation with signs of synovitis. Palpation of the patella evokes pain, but the patella is not ballotable and a fluid wave was not appreciated. The patient keeps the knee in flexion due to pain. She also has mild conjunctival injection, but the remainder of the physical examination is unremarkable.
Her leukocyte count is 9,500 cells/μL and erythrocyte sedimentation rate is 43 mm/hr. Radiographs of the knee do not reveal any fractures, but do confirm an effusion. Knee fluid aspiration shows a leukocyte count of 4,000 cells/μL. There are no crystals and Gram stain is negative. Blood and synovial fluid cultures are pending.
Which of the following is the best next step in managing this patient?

Question

A 22-year-old woman comes to the emergency department because of pain and swelling in her left knee for the past three days.  She denies fever, chills, skin rash, or dysuria.  However, she reports a one-week episode of diarrhea one month ago.  Stool cultures at that time were positive for Shigella flexneri, and the physician at the student health center prescribed ciprofloxacin for three days.  She has no other past medical history and her last menstrual period was one week ago.  She is sexually active with her new boyfriend.
Her temperature is 37.2 C (99 F), blood pressure is 117/68 mm Hg, and pulse is 87/min.  On physical examination, her left knee is tender to palpation with signs of synovitis.  Palpation of the patella evokes pain, but the patella is not ballotable and a fluid wave was not appreciated.  The patient keeps the knee in flexion due to pain.  She also has mild conjunctival injection, but the remainder of the physical examination is unremarkable.
Her leukocyte count is 9,500 cells/μL and erythrocyte sedimentation rate is 43 mm/hr.  Radiographs of the knee do not reveal any fractures, but do confirm an effusion.  Knee fluid aspiration shows a leukocyte count of 4,000 cells/μL.  There are no crystals and Gram stain is negative.  Blood and synovial fluid cultures are pending.
Which of the following is the best next step in managing this patient?

Quizplus · Accepted Answer

11ec193a_96b2_7d62_853d_d1b206c3542e_MD0002_00 This patient's presentation is consistent with reactive arthritis (formerly known as Reiter syndrome) following a Shigella diarrheal infection. Reactive arthritis (ReA) affects mainly younger adults and presents with asymmetric oligoarthritis after a preceding gastrointestinal or genitourinary infection. Patients may also develop enthesitis (pain at tendon insertion site), conjunctivitis, or oral ulcers. Diagnosis is clinical, since there is no gold standard diagnostic test. Clinicians should rule out other etiologies of arthritis before treating for suspected ReA. NSAIDs are initially preferred for treating ReA, but there is limited evidence that they shorten or alter the disease course. The majority of patients tend to have self-limited arthritis without the need for prolonged treatment. Patients who do not respond to NSAIDs may need systemic and/or intraarticular steroids (Choice A). Antibiotics help neither the arthritis nor, if present, underlying gastroenteritis, but they may be beneficial for underlying active genitourinary infection (e.g., Chlamydia) (Choice B). (Choice C) Disease-modifying agents (e.g., methotrexate or sulfasalazine) and anti-TNF agents are usually given to patients with chronic inflammatory arthritis refractory to NSAIDs and steroids. (Choice E) Disseminated gonococcal infections can present with either purulent monoarthritis or as a triad of skin rash, tenosynovitis, and polyarthralgia without purulent monoarthritis. Synovial fluid analysis usually shows a WBC count of > 50,000 cells/μL. Conjunctival symptoms, circinate balanitis, and keratoderma blenorrhagicum usually suggest reactive arthritis and are not seen in gonococcal infection. Educational objective: Reactive arthritis usually presents after a gastrointestinal or genitourinary infection with asymmetric oligoarthritis and enthesitis, conjunctivitis, or oral ulcers. Diagnosis is suspected clinically and NSAIDs are the preferred first-line therapy. Antibiotics help neither the arthritis nor, if present, underlying gastroenteritis, but they may be beneficial for active chlamydial genitourinary infection. __________ References: Reactive arthritis attributable to Shigella infection: a clinical and epidemiological nationwide study. (http://www.ncbi.nlm.nih.gov/pubmed/15550534) Symptomatic acute reactive arthritis after an outbreak of salmonella. (http://www.ncbi.nlm.nih.gov/pubmed/18528961)

A 22-Year-Old Woman Comes to the Emergency Department Because of Pain