The primary care pediatric nurse practitioner examines a child who has had stiffness and warmth in the right knee and left ankle for 7 or 8 months but no back pain. The nurse practitioner will refer the child to a rheumatology specialist to evaluate for which juvenile idiopathic arthritis subtype?

The primary care pediatric nurse practitioner examines a child who has had stiffness and warmth in the right knee and left ankle for 7 or 8 months but no back pain. The nurse practitioner will refer the child to a rheumatology specialist to evaluate for which juvenile idiopathic arthritis subtype?

• A. Enthesitis-related JIA
• B. Oligoarticular JIA
• C. Polyarticular JIA
• D. Systemic JIA

Answer: (B)

Oligoarticular JIA is defined by arthritis in a small number of joints during the first several months of disease, most commonly four or fewer joints and often involving large joints such as the knee and ankle. The child described has stiffness and warmth in two joints—the knee and the ankle—for several months, with no back pain or systemic symptoms. This pattern fits oligoarticular JIA best, so referral to rheumatology is to evaluate for this subtype. Enthesitis-related JIA would typically show tenderness at tendon insertion points (enthesitis) and often involves the back or sacroiliac joints, and it can occur with limited spinal symptoms. Polyarticular JIA involves five or more joints, often including small joints of the hands and feet. Systemic JIA presents with systemic features such as daily fevers and a rash, plus potential hepatosplenomegaly or serositis. The absence of back pain and systemic features, with arthritis limited to two joints, points away from those subtypes and toward oligoarticular JIA.

Oligoarticular JIA is defined by arthritis in a small number of joints during the first several months of disease, most commonly four or fewer joints and often involving large joints such as the knee and ankle. The child described has stiffness and warmth in two joints—the knee and the ankle—for several months, with no back pain or systemic symptoms. This pattern fits oligoarticular JIA best, so referral to rheumatology is to evaluate for this subtype.

Enthesitis-related JIA would typically show tenderness at tendon insertion points (enthesitis) and often involves the back or sacroiliac joints, and it can occur with limited spinal symptoms. Polyarticular JIA involves five or more joints, often including small joints of the hands and feet. Systemic JIA presents with systemic features such as daily fevers and a rash, plus potential hepatosplenomegaly or serositis. The absence of back pain and systemic features, with arthritis limited to two joints, points away from those subtypes and toward oligoarticular JIA.