A 14-year-old girl is brought to the clinic for leg pain. She first noticed achiness in the ankles 3 months ago after starting a daily walking routine on a local trail to improve her health. The aches tend to be worse in the morning but improve over the day. The pain spread to the knees, elbows, and wrists over the past month. Prior to this, the patient had been sedentary and spent most of her time indoors watching television. In addition to the walking routine, she has transitioned to a plant-based diet. The patient feels tired most days despite sleeping 9 hours a night. Her weight has improved from the 95th percentile to the 90th percentile over the past 3 months, and her height is stable at the 75th percentile. Temperature is 37.3 C (99.1 F), pulse is 80/min, and respirations are 16/min. Cardiopulmonary examination is normal. Bilateral ankles, knees, elbows, and wrists have mild swelling and tenderness to palpation. Which of the following medications is most appropriate for this patient's condition?
Juvenile idiopathic arthritis | ||||
Subtype | Frequency | Age of onset | Clinical features | Sex ratio |
Systemic | 10% | Age <18 |
| F = M |
Polyarticular | 40% | Age 2-5 |
| F > M |
Oligoarticular | 50% | Age 2-4 |
| F > M |
Juvenile idiopathic arthritis (JIA), a chronic autoinflammatory condition, is the most common cause of arthritis in children. Polyarticular JIA, as seen in this patient, involves ≥5 joints within 6 months of disease onset and is most commonly diagnosed in toddler and adolescent girls (ie, bimodal distribution).
Patients typically have joint pain and stiffness that is worse in the morning and improves over the course of the day. Symmetric involvement of the elbows, wrists, knees, and ankles (as in this patient) is most common. In addition, swelling of the small joints of the hands and feet may be seen, particularly in older children. Fever and other systemic symptoms (eg, rash) do not occur with polyarticular JIA.
Diagnosis is clinical, and first-line treatment is nonsteroidal anti-inflammatory drugs (eg, naproxen). Disease-modifying antirheumatic drugs such as methotrexate are also often required.
(Choices A and B) Ceftriaxone treats gonococcal arthritis, and doxycycline treats Lyme arthritis. Both present with a monoarticular or asymmetric oligoarticular arthritis (<5 joints), unlike this patient with symmetric involvement of ankles, knees, wrists, and elbows. In addition, skin findings are often associated with these 2 conditions: vesiculopustular lesions in gonococcal disease and a history of erythema migrans in Lyme disease. This patient has no cutaneous findings.
(Choice C) Levothyroxine is the treatment for hypothyroidism, which can cause fatigue and arthralgia (ie, joint pain). True arthritis (ie, joint inflammation), as in this case, does not occur. In addition, decreased height velocity is common in children with hypothyroidism, which is not seen in this case.
(Choice E) Inadequate sun exposure and poor dietary intake can cause vitamin D and calcium deficiency. Manifestations may include generalized bone and muscle pain due to poor bone mineralization. Unlike in this patient, the pain would not improve over the course of the day, and joint swelling would not be seen.
Educational objective:
Polyarticular juvenile idiopathic arthritis (JIA) presents as joint pain and stiffness involving ≥5 joints that is worse in the morning and improves over the course of the day. Individuals with polyarticular JIA are predominantly female, and the incidence peaks during adolescence and the toddler years. Nonsteroidal anti-inflammatory drugs (eg, naproxen) are the first-line treatment.