A 9-month-old boy is brought to the office by his parents due to swelling of the feet and hands for the past day. They first noted the swelling when the patient refused to hold his bottle of morning formula. He has also had poor feeding and fussiness. The patient has had no preceding upper respiratory symptoms and no known sick contacts. He was recently adopted from Nigeria, and his family history is not available. Vaccines are up to date. Temperature is 38.3 C (101 F) and pulse is 150/min. On examination, the dorsal surfaces of the hands and feet on both sides are swollen and tender to palpation. The remainder of the patient's joints appear normal. He is unable to grasp the examiner's hands due to restricted range of movement. No rash is seen on skin examination. X-rays of the feet and hands reveal soft tissue swelling. What is the most likely cause of this patient's presentation?

Question

A 9-month-old boy is brought to the office by his parents due to swelling of the feet and hands for the past day.  They first noted the swelling when the patient refused to hold his bottle of morning formula.  He has also had poor feeding and fussiness.  The patient has had no preceding upper respiratory symptoms and no known sick contacts.  He was recently adopted from Nigeria, and his family history is not available.  Vaccines are up to date.  Temperature is 38.3 C (101 F) and pulse is 150/min.  On examination, the dorsal surfaces of the hands and feet on both sides are swollen and tender to palpation.  The remainder of the patient's joints appear normal.  He is unable to grasp the examiner's hands due to restricted range of movement.  No rash is seen on skin examination.  X-rays of the feet and hands reveal soft tissue swelling.  What is the most likely cause of this patient's presentation?

Quizplus · Accepted Answer

11ec25c8_d6ab_25a8_bc81_f5fbf217fe3b_MD0003_00 Dactylitis (hand-foot syndrome) can be the earliest manifestation of vaso-occlusion in sickle cell disease (SCD). Vaso-occlusion of the blood vessels supplying the metacarpals and metatarsals occurs secondary to polymerization of sickled hemoglobin and increased red blood cell adhesion. This syndrome usually presents at age 6 months to 4 years with an acute onset of pain and symmetric swelling of the hands and feet. Low-grade fever is sometimes present. Initial radiographs reveal only soft tissue swelling, although in recurrent episodes they can reveal a mottled appearance of bone. Although most children with SCD in the United States are diagnosed by hemoglobin electrophoresis on newborn screening, the presence of dactylitis in a previously healthy child should prompt evaluation for SCD. Treatment involves hydration and pain control. (Choice A) Systemic juvenile idiopathic arthritis can present in early childhood with joint pain but most commonly presents with rash, high fever, and large joint involvement. Other autoimmune disorders (eg, psoriatic arthritis, ankylosing spondylitis) that can cause dactylitis classically occur in older children and adults. dactylitis (Choice B) Hypertrophic osteoarthropathy is a clinical syndrome comprising digital clubbing and bony swelling of the toes and fingers. Most commonly caused by pulmonary diseases (eg, cystic fibrosis) or malignancy, these changes develop chronically and are typically seen in older children or adults. digital clubbing (Choice C) Avascular necrosis, or osteonecrosis, of the femoral or humeral head is a complication in SCD caused by infarction of the articular cartilage and bony surface after chronically decreased blood flow. It presents with chronic, progressive hip pain with weight-bearing. (Choices E and F) Due to splenic autoinfarction, patients with SCD have poor splenic function and are thus prone to developing bacterial infections, including osteomyelitis. Osteomyelitis typically presents with swelling, fever, and pain localized to a single bone (rather than bilateral hands and feet). Staphylococcus aureus is the most common cause of bacterial osteomyelitis in all patients, and patients with SCD have an increased risk of Salmonella osteomyelitis. Educational objective: Dactylitis can be the earliest manifestation of vaso-occlusive disease in sickle cell disease and presents with the acute onset of bilateral hand and foot swelling and tenderness. References: Osteoarticular involvement in sickle cell disease. (http://www.ncbi.nlm.nih.gov/pubmed/23049406) Sickle cell disease in children: differentiating osteomyelitis from vaso-occlusive crisis. (http://www.ncbi.nlm.nih.gov/pubmed/19255393)

A 9-Month-Old Boy Is Brought to the Office by His