14 Week 10: Limp in a Child (Week of 10/30/2023)
Week 10: Limp in a child
DISCUSSION SESSIONS Week of 10/30/2023
Assignments Due: 10/31/2023 @8AM
PRIOR TO CLASS
- Read the syllabus entry below.
- Complete the required quiz (Quiz I) on Canvas.
- Complete pre-class case, Bernie.
- Prepare answers to discussion questions on pre-class cases:
- What are the most common causes of non-traumatic hip pain in children?
- What are the life-threatening/emergency conditions that can cause limp in children?
- Review the illness scripts distributed with the weekly email and which are available on Canvas
Learning Objectives
- Build a prioritized differential diagnosis for a limp in a pediatric patient that includes common and life/function threatening diagnoses.
- Identify the key history, physical exam, laboratory, and radiological findings that are useful in the evaluation of a pediatric patient presenting with a limp.
Limp is a common presentation in children and the evaluation can be challenging for clinicians for several reasons:
-History gathering can be difficult, especially when working with an infant or younger child who cannot articulate symptoms, and
-The difficulties in obtaining invasive testing or imaging studies.
The etiology of limp can span anatomically anywhere from the feet (e.g., plantar warts) to the hip joint (e.g., septic arthritis) to the back and can be due to vascular, infectious, neoplastic, autoimmune, or musculoskeletal causes. The most common cause of limp in children is pain and it is helpful to be able to differentiate an antalgic (painful) gait from a non-painful one as the latter suggests a neuromuscular cause.
We can base our pre-test probability of the causes of limp on data from prevalence studies. We can start by recognizing which etiologies are more common in certain age groups:
| Age | Disease Association |
| < 3 years | Non-accidental trauma, toddler fracture, neuromuscular disease (in addition to those in <6 year category) |
| <6 years | Septic arthritis, osteomyelitis |
| 3-8 years (especially <4) | Transient synovitis (slightly more common in boys) |
| 4-10 years | Legg-Calve-Perthes Disease (boys 4:1 ratio),
growing pains, osteomyelitis |
| Boys 10-14 years | Slipped capital femoral epiphysis (SCFE) |
| > 10 years | Osteomyelitis, transverse myelitis, discitis, Guillian-Barre syndrome |
The acuity can also help us with pre-test probability:
| Acuity | Disease Association |
| Acute | Transient synovitis, fracture, soft tissue injury (muscle, ligament, tendon), septic arthritis |
| Sub-acute/chronic | Legg-Calvé-Perthes disease, osteomyelitis, SCFE*, Juvenile Idiopathic Arthritis (JIA), malignant and benign tumors*, developmental dysplasia of hip (leading to avascular necrosis), foreign body in foot (e.g., glass) |
| *Can present acutely after trauma or (more commonly) as chronic hip pain/limp; pathologic fracture may present acutely in case of a tumor | |
The presence of specific historical findings can be very informative as well:
| Historical Finding | Disease Association |
| Trauma | Fracture, soft tissue injury (muscle, ligament, tendon), SCFE |
| Fever | Osteomyelitis, septic arthritis, Systemic JIA, transient synovitis (low grade), rheumatic fever, systemic lupus erythematosus (SLE) |
| Rash | JIA, Henoch-Schonlein purpura (HSP), SLE, gonococcal arthritis |
| Morning Stiffness | JIA (especially oligoarticular and enthesitis-related) |
| Recent URI | Transient synovitis |
| Findings of hypothyroidism or hypopituitarism | SCFE |
| Nocturnal pain, especially if cyclic | Malignancy and benign bone tumors |
| Geography/tick exposure | Lyme |
| Sickle cell, prior septic arthritis, SCFE | Avascular necrosis of femoral head |
| Athlete | Avulsion fracture of anterior superior iliac spine, shin splints, stress fracture, apophysitis |
Putting all of this together can help us with a targeted approach to our exam along with use of imaging or laboratory studies to come up with the final diagnosis.
RESOURCES FOR FURTHER READING
- UpToDate:
“Evaluation of the child with a limp”
“Overview of causes of limp in children”