A 29-year-old man who recently completed a course of antibiotics for nongonococcal urethritis secondary to Chlamydia trachomatis presents with diffuse joint pain. The patient describes the pain as particularly bothersome in his low back and left knee. The patient is otherwise healthy and has no other complaints. Physical examination reveals an afebrile man with normal vital signs. The patient’s left knee is markedly swollen, erythematous, and exquisitely tender to palpation. Head and neck examination reveals bilateral redness in the eyes with epiphora. Joint aspiration is performed which reveals a leukocyte count of 11,000/mm3 . Synovial fluid analysis also reveals a predominance of polymorphonuclear leukocytes.
Which of the following is associated with this patient’s condition?
HLA-B27. This patient is presenting with the classic triad found in reactive arthritis (Reiter syndrome), including nongonococcal urethritis, arthritis, and conjunctivitis (best remembered by the phrase “can’t see, can’t pee, can’t climb a tree”). Reactive arthritis is a seronegative spondyloarthropathy, referring to the fact that it is negative for rheumatoid factor (RF). Think “PAIR” (Psoriatic arthritis, Ankylosing spondylitis, Inflammatory bowel disease, and Reactive arthritis) for remembering the seronegative spondyloarthropathies. These diseases are associated with an increased incidence of HLA-B27. (A) Chronic hyperuricemia can be seen in chronic gout and is best treated with allopurinol. (C) Articular cartilage degradation is seen in osteoarthritis. (D) Inflammation of the synovium is seen in rheumatoid arthritis.
A 39-year-old woman with a history of rheumatoid arthritis presents for routine care. The patient’s symptoms are well controlled on her current medication regimen. Routine laboratory values reveal the following:
Which of the following is this patient taking for her rheumatoid arthritis?
Methotrexate. The patient in this question has rheumatoid arthritis and is presenting with a macrocytic anemia (MCV >100 fL). Of the four choices, only methotrexate can cause a macrocytic anemia. Methotrexate is a disease-modifying antirheumatic drug (DMARD), which inhibits the metabolism of folic acid by inhibiting dihydrofolate reductase. Other important side effects include stomatitis, lung fibrosis, rash, and pancytopenia. Therefore, patients on methotrexate need to have their blood counts (CBC) checked every 3 months. (B) Cyclosporine is an immunosuppressant drug used commonly after organ transplantation. It is associated with increased viral infection, nephrotoxicity, hypomagnesemia, and hepatotoxicity. (C) Corticosteroids are used in the treatment of rheumatoid arthritis (RA) and side effects include osteoporosis, impaired wound healing, and other effects seen in Cushing syndrome. (D) Hydroxychloroquine is also a DMARD used in the treatment of RA, but its side effects include visual problems and hemolytic anemia found in G6PD deficiency.
A 4-year old boy presents with fever, swollen lymph nodes, and headache for the past 3 days. Physical examination demonstrates a fever of 38.4°C and a heart rate of 110 beats per minute. There is conjunctival injection, bilateral swelling of the anterior cervical lymph nodes, and a morbilliform rash over the upper and lower extremities. Oral examination reveals a diffusely red and enlarged tongue.
Which of the following is likely to develop if this condition goes untreated?
Coronary artery aneurysm. This patient is presenting with an autoimmune disorder called Kawasaki disease, also known as mucocutaneous lymph node syndrome. This is a large- and medium-sized vessel vasculitis mostly seen in children under the age of 5. It affects many organ systems including the blood vessels, skin, mucous membranes, and lymph nodes. The most rare but serious effect is on the heart, where it can cause fatal coronary artery aneurysms in untreated children. Unlike Wegener granulomatosis, microscopic polyangiitis, and Churg–Strauss syndrome, Kawasaki disease is not associated with ANCA antibodies. The diagnosis of Kawasaki disease relies on the presence of fever for at least 5 days in addition to four out of five of the following criteria (known as CRASH): Conjunctivitis (bilateral), Rash (usually trunk), Aneurysms (coronary), Strawberry tongue, and/or Hand and feet erythema. Cervical lymphadenopathy can also be added to this list. Treatment consists of intravenous immunoglobulin (IVIG, for prevention of coronary vasculitis) and high-dose aspirin (which is usually avoided in children due to Reye syndrome). Early treatment is critical to avoid the risk of coronary aneurysm.
(A) Kawasaki disease typically shows normocytic anemia and thrombocytosis; it does not result in leukemia. (B) Blindness is a complication of another large-vessel vasculitis called giant cell (or temporal) arteritis. (D) Kawasaki disease is not associated with the development of pulmonary embolism or pro-coagulative states.
A 32-year-old man of Turkish descent presents with painful oral and genital ulcers. He reports two previous episodes of oral ulcers that resolved within 2 weeks. The patient also reports blurred vision, diarrhea, and a cough. Physical examination reveals nonscarring oral mucocutaneous aphthous ulcerations and several discrete ulcerations on the shaft of the penis. The rest of the dermatologic examination reveals several hyperpigmented nodules on the bilateral anterior legs that are painful to palpation.
Which of the following is the most likely diagnosis in this patient?
Behçet disease. This patient is presenting with recurrent oral ulcers, genital ulcers, blurred vision (likely secondary to anterior uveitis), erythema nodosum on the anterior legs, and diarrhea. Given this constellation of symptoms in combination with his Turkish descent, he likely has Behçet disease. This disease is a rare immune-mediated systemic vasculitis that often presents with mucous membrane ulceration and ocular problems. The triad that is often tested is recurrent oral aphthous ulcers, genital ulcers, and uveitis. This syndrome is much more common in Turkish, Central Asian, and Middle Eastern communities (commonly called the “Silk Road Disease” based on the old silk trading routes in the Middle East and Central Asia). The official diagnosis occurs when recurrent oral ulcers are present with two additional findings from the following: recurrent genital ulcers, either anterior uveitis or posterior uveitis, skin findings (papulopustular lesions, folliculitis, erythema nodosum, or acne in postadolescents not on corticosteroids), and/or positive pathergy test (papule >2 mm in diameter 24 to 48 hours or more after needle-prick).
(B) HSV infection results in small grouped vesicles on an erythematous base. This patient has aphthous ulcers, not herpetic vesicular lesions. (C) Systemic lupus erythematosus (SLE) results in oral ulcers, but is also associated with arthritis, hematologic abnormalities, malar rash, and other findings not seen in this patient. (D) Sarcoidosis can cause erythema nodosum (as seen on dermatologic examination in this patient) and cough; however, it also presents with dyspnea and sometimes chest pain. Ulcerations are not seen in sarcoidosis.
A 61-year-old man with a history of chronic alcoholism and parathyroid adenoma presents with pain in his left knee for the last 2 days. He denies fevers, chills, night sweats, or any history of trauma to the knee, but does endorse abdominal pain and constipation. Physical examination is significant for tenderness and erythematous skin overlying the left knee. There is also marked swelling of the left knee. Laboratory findings reveal an elevated calcium level (12.1 mg/dL).
If joint aspiration is performed, which of the following will be seen on synovial fluid analysis?
Positively birefringent rhomboid-shaped crystals. This patient has a history of parathyroid adenoma that is likely causing hypercalcemia secondary to hyperparathyroidism. Patients with hypercalcemia are at risk for developing pseudogout, a rheumatologic disease with diverse symptoms and signs arising from the accumulation of calcium pyrophosphate dihydrate crystals in the connective tissues. It commonly presents with acute onset, painful monoarthropathy of the knee. Joint aspiration with synovial fluid analysis confirms the diagnosis, showing rhomboid-shaped crystals that are positively birefringent. (A) Negatively birefringent needle-shaped crystals describe gout, which also presents with acute onset monoarthropathy, but usually affects the first metatarsophalangeal joint of the foot. Furthermore, gout is not triggered by hypercalcemia. (C) Neutrophil predominant synovial fluid with gram-positive cocci is diagnostic of septic arthritis. This patient has no fever, making septic arthritis highly unlikely from the clinical picture alone. (D) Normal synovial fluid findings are not the norm in the setting of pseudogout.