When It’s Not Just “Growing Pains”

Differentiating between a benign etiology and a potentially destructive, chronic process is critical

 

BY MIRIAM PARSA, MD

A 4-year-old Caucasian girl is evaluated for limp. Her parents are unclear about the duration of her symptoms, although they believe her complaints started after she was playing with her brother three months before. Her parents have observed the girl walking “like her grandmother” every morning, with marked improvement in her gait one hour after moving around. She has no history of rash, fever, weight loss or severe pain complaints. On physical examination, her vital signs are normal, her left knee is swollen with a 20 degree flexion contracture, and her left leg is 1.5cm longer than her right leg.


Joint pain is a common complaint in the pediatric population, and etiologies include trauma, hypermobility and chronic inflammatory arthritis, such as juvenile idiopathic arthritis. Differentiating between a benign, self-limited etiology and a potentially destructive, chronic process is critical to the preservation of growing bones and cartilage.


Miriam Parsa, MD

 

The etiology of joint pain can be roughly divided into two categories: mechanical versus inflammatory. Mechanical or non-inflammatory causes include pes planus, hindfoot valgus or hypermobility. Inflammatory causes include infectious, post-infectious or autoimmune mediated. Distinguishing between mechanical and inflammatory processes, and the subsequent need for a pediatric rheumatology consult, may be straightforward after a detailed history, thorough physical examination and focused laboratory investigation are performed.

 

“Growing pains” are a benign cause of pain in children and usually resolve within one to two years of onset. They are characterized by nocturnal pain without objective musculoskeletal manifestations. The pain complaints are generally localized to the bilateral lower extremities and are relieved by massage, heat or NSAIDs. Red flags necessitating further workup include systemic symptoms (i.e., fevers, weight loss), persistent pain during the day, objective musculoskeletal exam abnormalities, limping and unilateral pain.

 

Other causes of joint pain in children
Mechanical or non-inflammatory causes of joint pain in children may include joint hypermobility, hindfoot valgus or pronation, genu recurvatum or pes planus. A typical presentation of a child with mechanical causes of joint pain contains a history of pain after activity, relief with rest and typical physical examination findings. Further questioning may reveal a history of pain exacerbation of the knees, ankles and feet when the child does not wear supportive shoes during physical activity.

 

Acute onset joint pain that is monoarticular, severe in quality and accompanied by fever is suggestive of septic arthritis, an orthopedic emergency because of the rapid cartilage destruction if treatment is delayed. When joint pain is monoarticular and localizes to the periarticular region, is severe in quality and is accompanied by weight loss and/or abnormal CBC, then malignancy, such as acute lymphoblastic leukemia, should be considered.

 

Our 4-year-old girl in the case presentation was diagnosed with ANA+ oligoarticular juvenile idiopathic arthritis (JIA). She demonstrated classic symptoms of chronic inflammatory arthritis (daily, worst in the morning, not severe in quality and improves with activity). Because of her high risk for anterior uveitis (young age, new JIA diagnosis, ANA+), she will see a pediatric ophthalmologist every three months. Her arthritis was treated successfully with an intra-articular steroid injection and she resumed participating in all activities.

 

 

 << Return to Spring 2014 CCH Magazine

 

032014