17 Flashcards
Lyme disease
Presentation
Dx
Complications
Lyme disease is a tick-borne illness caused by Borrelia burgdorferi.
Presentation
It has a characteristic rash (erythema migrans) and is associated with fever, malaise, fatigue, and headache.
Diagnosis
The diagnosis is made clinically, based on the rash and a constellation of other symptoms.
Complications
Arthritis is the second most common manifestation of Lyme disease and typically begins 4 weeks after the skin lesion.
The large joints closest to the rash are most commonly affected.
The arthritis may relapse or occur only once.
Developmental dysplasia of the hip
RF
Screening
Complications
DDH refers to a group of conditions in infants where the femoral head is not properly aligned with the acetabulum. The spectrum includes hips that are dysplastic, dislocatable, subluxated (partially dislocated), and dislocated.
Risk Factors
There are many risk factors for DDH, including:
Female sex
Breech delivery
Family history of DDH
Screening
Important screening physical examination maneuvers in newborns to detect DDH are the Ortolani and Barlow tests:
The Ortolani maneuver assesses for a dislocated hip by abduction of the flexed hip with gentle anterior force.
The Barlow maneuver assesses for a dislocatable hip by adduction of the flexed hip with gentle posterior force.
Complications
Misalignment can lead to abnormal growth of the hip joint and permanent disability.
Diff dx of acute refusal to walk
More likely
Less likely
More likely
Leukemia
Leukemia must always be considered in a child refusing to walk.
Replacement of bone marrow by leukemic cells can cause bone pain that presents as limp, refusal to walk, or localized discomfort of the jaw, long bones, vertebral column, hip, scapula or ribs.
These symptoms may precede systemic signs such as fever and weight loss.
Osteomyelitis
Osteomyelitis is an infection of the bone, usually bacterial in origin, most often caused by Staphylococcus aureus and, before the era of routine immunization, Haemophilus influenzae (Hib).
In toddlers, it usually presents with pain and refusal to bear weight (when affecting a leg bone).
A history of fever is present in about half of cases.
Because of its usually indolent presentation, diagnosis can be delayed by up to 5 to 10 days.
Osteomyelitis in the ilium may present with hip pain.
Reactive arthritis
This is an inflammatory process associated with an infection outside of the joint, most often in the gastrointestinal or genitourinary tract.
The classic association with urethritis and conjunctivitis is uncommon in children.
Children are frequently afebrile at presentation.
Septic arthritis
While patients with septic arthritis almost always have a history of high fever, this diagnosis remains important to include.
Transient synovitis
Acute onset of hip pain with perhaps no other constitutional symptoms is typical of transient synovitis.
Transient synovitis often occurs during or following a URI, and a low-grade fever is not inconsistent with this diagnosis. (If the fever was high, you would be concerned about the possibility of septic arthritis.)
Trauma
Minor accidental trauma such as a sprain or an occult fracture is possible after a fall.
The possibility of non-accidental trauma must always be considered as well.
Less likely (these diagnoses would be considered if the presentation was less acute) Juvenile idiopathic arthritis (JIA) Formerly called juvenile rheumatoid arthritis (JRA), JIA refers to a group of disorders characterized by chronic inflammation of the joints. To meet diagnostic criteria, children must be less than 16 years of age and have arthritis in at least one joint for more than six weeks. There are several subtypes, including:
Systemic (includes constitutional symptoms such as fever and rash);
Oligoarthritis (previously called pauciarticular, this type of oligoarthritis typically affects the knee; onset of the arthritis is acute, and it is associated with an asymptomatic iridocyclitis);
Polyarthritis (rheumatoid factor positive and rheumatoid factor negative);
Psoriatic arthritis;
Enthesitis-related arthritis; and
“Other arthritis” (has overlapping features with multiple categories or does not meet full criteria for one category).
Slipped capital femoral epiphysis (SCFE)
Most common hip disorder in adolescents.
Characterized by posterior displacement of the capital femoral epiphysis from the femoral neck through the cartilage growth plate.
Causes limp and impaired internal rotation.
Presentation: Most commonly, months of vague hip or knee symptoms and limp with or without an acute exacerbation.
Etiology: Not clearly defined. Occurs more commonly in obese adolescents, suggesting that mechanical strain on the growth plate could be at least partially responsible for the slip. Endocrine factors also may be important.
Diagnosis: Usually with plain film showing posterior displacement of the femoral head, like an ice-cream scoop slipping off a cone.
Prognosis: Depends on degree of slip and accompanying complications, particularly avascular necrosis of the femoral head and destruction of the articular cartilage.
Therapy usually involves pinning to stabilize the epiphysis but no manipulation.
Legg-Calve-Perthes disease
Also called avascular necrosis of the capital femoral epiphysis.
Most commonly affects boys between the ages of 4 and 10.
Presentation: Typically indolent or chronic pain rather than acute.
Etiology: Various etiologies have been postulated, including infectious, trauma, developmental, and prothrombotic conditions.
Natural history: Typically self-resolving, but may lead to complications including femoral head deformity and degenerative arthritis.
Treatment: Usually involves referral to an orthopedic surgeon, with the goal of preventing damage to the hip by containing the femoral head within the acetabulum—ideally through conservative methods.
Avascular necrosis of the femoral head
Necrosis of the bone due to loss of blood supply.
May be caused by traumatic or nontraumatic factors.
Observing patient with musculoskeletal complaint
Hip pain secondary to an effusion (associated with septic arthritis of the hip and transient synovitis) is relieved when the patient “opens” her hip capsule by holding her hip in flexion and external rotation. On the other hand, leg pain associated with osteomyelitis is not position-dependent, but will increase with weight-bearing so the child will avoid standing alone.
Evaluation of a painful hip
Labs etc
Measures of Inflammation
The most useful laboratory tests are:
White blood cell count (obtained by ordering a CBC)
CRP
ESR
Each of the above measures inflammation to some degree. Both ESR and CRP are non-specific measures of inflammation, so they can be elevated in many conditions, including:
Infections
Malignancies
Inflammatory conditions
Juvenile idiopathic arthritis and leukemia could also elevate these lab tests.
Transient synovITIS and septic arthrITIS are both inflammatory processes. However, the more serious condition of septic arthritis should be associated with greater increases in the WBC, CRP and ESR.
Culture for Organism
Septic arthritis may occur due to bacteria entering the joint space via the blood. By ordering a blood culture it is possible that you might identify the organism causing the joint infection.
Visualization
An x-ray of the hip is also needed to help rule out the possibility of trauma.
Transient synovitis vs septic arthritis
Both are inflammatory processes, so WBC, CRP and ESR elevation seen in both, but those labs would be much higher in septic arthritis
Septic arthritis of the hip Dx Synovial fluid composition Common organisms Tx
Diagnosis
An ultrasound of the hip is useful for identifying an effusion and for guiding a needle aspiration, or arthrocentesis. Arthrocentesis is a difficult procedure that is best performed by an experienced orthopedic surgeon.
Characteristics of Synovial Fluid
Turbid appearance
Increased white cell count, predominantly polymorphs
Low glucose
Gram stain of the fluid should show bacteria on gram stain and a sample needs to be sent for culture.
Most Common Causative Organisms
Staphylococcus aureus
Streptococcus (neonate: group B; infant and older child: Group A and Streptococcus pneumoniae)
Haemophilus influenzae type b (in unimmunized children)
Neisseria gonorrhea (adolescents)
Kingella kingae (in children less than 4 years) Treatment
Empiric intravenous antibiotic coverage should begin immediately after the joint aspiration and then potentially changed once a specific organism and its antibiotic sensitivity is identified.
Once septic arthritis of the hip is confirmed, surgical incision and drainage may be necessary to remove debris and reduce the pressure in the hip joint.
Septic arthritis of the hip requires a prolonged course of antibiotics and may require repeated aspiration or incision and drainage of the hip to remove reaccumulated purulent effusion.
Transient synovitis of the hip Etiology Tx Duration of sxs Recurrence and prognosis
This is a relatively common condition resulting from inflammation and swelling of the tissues around the hip joint and can often be seen in children who have recently had a cold.
Etiology
The etiology of transient synovitis of the hip is unknown. However, studies have shown that between 32 and 50 percent of children presenting with transient synovitis had a recent upper respiratory infection. Most patients are afebrile or have a low-grade fever. Some propose transient synovitis to be a post-infectious viral syndrome. Others point out that most children with or without transient synovitis have had a recent URI.
Treatment
Rest and ibuprofen.
Duration of Symptoms
The pain usually completely resolves within 3 to 10 days.
Recurrence and Prognosis
There is a small chance of recurrence, but no serious or long-lasting consequences of this condition. It does not predispose the individual to arthritis in the future.
