Originally published at Pediatric EM Morsels on January 10, 2014. Reposted with permission.

Follow Dr. Sean M. Fox on twitter @PedEMMorsels

This little Morsel stems from a intellectually fun conversation with Dr. Modisett (for those of you overseas, Dr. Modisett is one of our brilliant and illustrious Chief Residents at Carolinas – yes, I am spoiled).  This is another great reason to discuss not throwing antibiotics at every kid with an ear.

Serum Sickness Basics

• Serum Sickness is considered a Type III hypersensitivity reaction.
  • Follows the administration of Foreign Proteins or Chemicals.
  • Antigen-antibofy complexes get deposited along the basement membranes of small vessels.
• An inflammatory response occurs that leads to joint, skin, and systemic manifestations.
• The true pathophysiology is unclear.
• It is a self-limited condition, but the presentation can be quite dramatic and concerning to families.
  • 50% of children, in one study, required hospitalization due to severe symptoms.

Serum Sickness Presentation

• Serum Sickness and “Serum Sickness-Like Reactions” are similar in presentation.
• Fever
• Rash (most often uricaria)
• Arthralgias/Arthritis
• Malaise
• Lymphadenopathy
• Proteinuria

• Serum Sickness – Like Reaction

  • Often used when referring to medication associated reactions.
  • Differs from Serum Sickness in that it infrequently has associated proteinuria and lymphadenopathy.
  • More often reported in children.
  • More likely to occur during or following a second course of antibiotics (particularly Cefaclor).
  • Often occurs within the first 1 to 3 weeks after initiation of the offending drug.

Serum Sickness Causes

• Anti-venom created from Horse Serum.
  • Historically, the term was derived the administration of Horse Serum that had been given to treat Diptheria. Ah, yes… the good ol’days.
• Antibiotics
  • Penicillins / Amoxicillin
  • Cefaclor
  • Cefprozil
  • Cefazolin
  • Ciprofloxacin
  • Minocycline
• Thiazide Diuretics
• Many other medications.

Serum Sickness Treatment

• Steroids and antihistamines have been used — no real data to show utility.
• Stop offending agent!
• Give analgesics!
• Supportive care.

References