Review – Kaplan Pediatrics: Rheumatic and Vasculitis Disorders

Dec 5, 2019 admin NHI KHOA 0

Review – Kaplan Pediatrics: Rheumatic and Vasculitis Disorders

JUVENILE IDIOPATHIC ARTHRITIS (JIA)

A 7-year-old girl complains of pain and swelling of the left wrist and right knee off and on for the past 3 months. She has been previously healthy. The pain is worse in the morning and improves throughout the day. Physical examination is remarkable for swelling and effusion of the right knee, with decreased range of motion.

 

 

  • Definition—idiopathic synovitis of peripheral joints associated with soft-tissue swelling and joint effusion
  • Pathophysiology
    • Vascular endothelial hyperplasia and progressive erosion of articular cartilage and contiguous bone
    • Immunogenetic susceptibility and an external trigger
    • DR8 and DR5
  • Clinical presentation
    • Morning stiffness; easy fatigability
    • Joint pain later in the day, joint swelling, joints warm with decreased motion, and pain on motion, but no redness
  • Criteria for diagnosis
    • Age of onset: <16 years
    • Arthritis in one or more joints
    • Duration: ≥6 weeks
    • Onset type by disease presentation in first 6 months
    • Exclusion of other forms of arthritis, other connective tissue diseases and vascu- litides, Lyme disease, psoriatic arthritis, inflammatory bowel disease, lymphop- roliferative disease
  • Category of disease with 3 types of onset
    • Pauciarticular (fewer than 5 joints)—joints of lower extremity (hip never the presenting joint; almost never upper extremities)
−   Polyarticular (5 or more joints):
  • Both large and small joints (20–40 may be involved); resembles presenta- tion in adult
  • Rheumatoid nodules on extensor surfaces of elbows and Achilles tendon (represents a more severe course)

Note

A positive rheumatoid factor in JIA is indicative

of a poor prognostic outcome.

 

 

  • May have cervical spine involvement
−   Systemic onset:
  • Arthritis and prominent visceral involvement¾hepatosplenomegaly, lymphadenopathy, serositis, iridocyclitis
  • Daily temperature spikes to at least 39°C (102°F) for 2 or more weeks
  • Characteristic salmon-colored evanescent rash (linear or circular) mostly on trunk and proximal extremities
  • Labs
    • No best test
    • Increased acute-phase reactants; increased anemia of chronic disease
    • Increased antinuclear antibodies (ANA) in 40–85%, mostly with poly- and pauciarticular disease
    • Positive rheumatoid factor (RF+)¾typically with onset of disease in an older child with polyarticular disease and development of rheumatoid nodules
  • Treatment
    • Most with pauciarticular disease respond to nonsteroidal antiinflammatory drugs (NSAIDs) alone
    • Additional treatment¾methotrexate (safest and most efficacious of second- line agents); azathioprine or cyclophosphamide and biologicals
    • Corticosteroids (few indications):
      • Overwhelming inflammation
      • Systemic illness
      • Bridge treatment
    • Ophthalmology follow up; physical therapy (PT)/occupational therapy

 

Table 18-1. JRA Prognosis
Category Serology Major Problems Outcome
Polyarticular disease RF+ Older girls; hand and wrist; erosions, nodules, unremitting Poor
ANA+ Younger girls Good
Seronegative ¾ Variable
Pauciarticular disease ANA+ Younger girls; chronic iridocyclitis Excellent (except eyes)
RF+ Polyarthritis, erosions, unremitting Poor
HLA B27 Older males Good
Seronegative ¾ Good
Systemic ¾ Pauciarticular Good
¾ Polyarticular Poor

 

 

 

SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

A 10-year-old girl presents with fever, fatigue, and joint pains. Physical examination is remarkable for a rash on the cheeks, swelling of the right knee, and pericardial friction rub. Initial laboratory tests reveal anemia and an elevated blood urea nitrogen and creatinine.

 

  • Etiology
    • Autoantibodies against self-antigens
    • Unknown etiology; probably multifactorial
    • Increased levels of anti–double-stranded DNA (anti-dsDNA)
    • Association with HLA B8, DR2, and DR3
−   Some are drug-induced, especially with anticonvulsants, sulfonamides, and antiarrhythmics
  • Exacerbations promoted by exposure to sunlight and infections
  • Clinical presentation
    • Onset before age 8 unusual; females
    • Most frequent presentation: fever, fatigue, arthralgia, arthritis, rash
    • Skin—malar (butterfly) rash, discoid lesions, livedo reticularis; photosensi- tivity; also vasculitic-appearing erythematous macules on fingers, palms, and soles; purpura and Raynaud phenomenon
−   Renal—glomerulonephritis, nephrotic syndrome, hypertension, renal failure
  • Cardiovascular—pericarditis; Libman-Sacks endocarditis; cardiomegaly, heart failure
  • Neurologic—seizures, stroke, aseptic meningitis, chorea, psychiatric changes
  • Pulmonary—pleuritic pain, pulmonary hemorrhage
  • Hematologic—Coombs-positive hemolytic anemia, anemia of chronic disease, thrombocytopenia, leukopenia
  • Serositis—pleural, pericardial, and peritoneal often with hepatosplenomegaly and lymphadenopathy
  • Gastrointestinal vasculitis—pain, diarrhea, bleeding, hepatitis
−   Arterial and venous thromboses—suggestive of antiphospholipid syndrome (plus recurrent fetal loss, livedo reticularis, Raynaud phenomenon); can be associated with the lupus anticoagulant
  • Diagnosis (see margin note)
  • Labs
−   Best screen: ANA
  • Best test: anti-dsDNA (more specific for lupus; reflects disease activity)
  • Anti-Smith Ab–specific for SLE; does not measure disease activity
  • Treatment
−   NSAIDs if no renal disease
  • Methotrexate

– Biological DMARDs (disease-modifying antirheumatic drugs)

 

Note

A pregnant woman with SLE will transfer IgG autoantibodies (usually anti-Ro) across the placenta at 12 to 16 weeks.

This can cause a variety of manifestations, the most important being congenital heart block. All are temporary, except for the heart block, which may require permanent pacing.

 

Note

ANA Abs are sensitive.

Anti-Smith Abs are specific.

 

Note

Diagnosis of SLE— “M.D. Soap ’n Hair”

Malar rash Discoid rash Serositis Oral ulcers ANA-positive

Photosensitivity Neurologic disorders Hematologic disorders Arthritis

Immune disorders (LE [lupus erythematosus] prep test, anti-DNA, Smith)

Renal disorders

 

 

  • Patients with thrombosis and antiphospholipid syndrome should receive antico- (use heparin during pregnancy)
  • Steroids for kidney disease and acute disease
  • Cyclophosphamide for severe disease

 

 

Note

The most serious sequelae of Kawasaki disease are cardiac-related.

 

 

 

 

 

Note

Any child suspected of having Kawasaki disease should have an echocardiogram.

KAWASAKI DISEASE

An 18-month-old has had fever for 10 days. He now has conjunctival injection, a very red tongue and cracked lips, edema of the hands, and a truncal rash.

 

  • Severe acute vasculitis of all blood vessels but mostly affecting medium-sized arteries, especially coronary; worldwide (higher in Asians)
  • Now the leading cause of acquired heart disease in United States and Japan (with- out treatment, 20% develop coronary artery abnormalities)
  • 80% are under 5 years old; occasionally teenagers and younger adults
  • Diagnostic criteria
−   Fever for ³5 days not improved with ibuprofen or acetaminophen, plus 4 of the following 5 criteria:
  • Bilateral bulbar conjunctivitis without exudate (may have early anterior uve- itis)
  • Intraoral erythema, strawberry tongue, dry and cracked lips
  • Erythema and swelling of hands and feet; desquamation of fingertips 1–3 weeks after onset; may involve entire hand or foot
  • Various forms of rash (but not vesicular); diapered children may have peri- neal desquamation
  • Nonsuppurative cervical lymphadenitis, usually asymmetric, >1.5 cm
  • Other findings:

} Extreme irritability

} Aseptic meningitis

} Diarrhea

}  Hepatitis

} Hydrops of the gallbladder

} Urethritis with sterile pyuria

} Otitis media

} Arthritis

  • Cardiac findings:

} Early myocarditis (50%) with tachycardia and decreased ventricular function

} Pericarditis

} Coronary artery aneurysms in the second to third week

  • Lab abnormalities
    • WBC—normal to increased; neutrophils and bands
    • Increased ESR

 

 

 

  • Normocytic anemia of chromic disease
  • Platelets high/normal in week 1, then significant increase in weeks 2–3 (often more than a million)
  • Sterile pyuria
  • Increased hepatic transaminases
  • Cerebrospinal fluid (CSF) pleocytosis
•      Management: most important test is 2D echocardiogram; repeat at 2–3 weeks and, if normal, at 6–8 weeks. Also get ECG, follow platelets.
  • Treatment
−   Acute—intravenous immunoglobulin (IVIg) and high-dose aspirin
  • Low-dose aspirin (3–5 mg/kg/day) at start of subacute phase (afebrile)
  • Infleunza vaccines if in winter (Reye syndrome)
•      Prognosis—no evidence of long-term cardiovascular sequelae in those who do not have coronary abnormalities within 2 months of onset

 

HENOCH-SCHÖNLEIN PURPURA (HSP)

A 5-year-old boy is seen with maculopapular lesions on the legs and buttocks. He complains of abdominal pain. He has recently recovered from a viral upper respiratory infection. Complete blood cell count, coagulation studies, and electrolytes are normal. Microscopic hematuria is present on urine analysis.

 

  • IgA-mediated vasculitis of small vessels (IgA and C3 in skin, renal glomeruli, and gastrointestinal tract); most common cause of nonthrombocytopenic purpura in children
  • Usually follows an upper respiratory infection
  • Children usually 2–8 years of age; usually in winter, more males than females
  • Clinical presentation
    • Low-grade fever and fatigue
    • Hallmark—pink, maculopapular rash below waist; progresses to petechiae and purpura (red → purple → rusty brown); crops over 3–10 days (at times in intervals up to 3–4 months)
    • Gastrointestinal:
      • Intermittent abdominal pain
      • Occult blood in stools
      • Diarrhea or hematemesis
      • Intussusception may occur
    • Arthritis unusually large, weight-bearing joints
    • Renal—25–50% with glomerulonephritis or nephrosis
    • Hepatosplenomegaly, lymphadenopathy
    • Rarely, CNS (seizures, paresis, coma)
  • Laboratory studies
    • Increased platelets, WBCs, ESR

 

 

 

 

 

Note

Kawasaki disease is one of the few instances in pediatrics for which you would use aspirin. (It is usually avoided because of the risk of developing Reye syndrome.)

 

 

 

  • Anemia
−   Increased IgA, IgM
  • May have anticardiolipin or antiphospholipid antibodies
  • Urine—RBCs, WBCs, casts, albumin
  • Diagnosis
    • Classic clinical presentation
    • Definitive diagnosis (rarely needed) with skin biopsy
    • Renal biopsy shows IgA mesangial deposition and occasionally IgM, C3, and fibrin
  • Treatment
    • Symptomatic treatment for self-limited disease (constitutional symptoms, rash, arthritis)
    • Intestinal complications—corticosteroids oral or intravenous → dramatic improvement of gastrointestinal signs and symptoms (can recur for as long as 3 years)
    • Renal—same for any form of renal disease
  • Complications—renal insufficiency/failure, bowel perforation, scrotal edema, and testicular torsion; chronic renal insufficiency occurs in <1% and of those,

<0.1% result in failure

 

 

 

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