Transcript Document

Case Conference
K. Myra Lalas
PGY 3
CC: rash and joint pain
History of Present Illness
• 2 days PTA, (+) itchy, reddish wheals on back
then spread to torso, chest, and extremities
• Went to PMD and was prescribed Benadryl
and Hydrocortisone, which gave some relief
• On the day of admission, (+) swelling,
redness, warmth, and pain of both knees ( R
> L), ankles (R > L), L elbow
• No morning stiffness, nails don’t turn funny
colors when cold
Review of Systems
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No fever
No cough or runny nose
No vomiting
No diarrhea
Good PO
No sick contacts
No recent travel
1st episode
Past Medical History
• Staghorn calculus s/p removal of stones in the
right kidney 3/2010
Family History
• Osteoarthritis- grandfather
• No lupus, no JIA, no scleroderma
• No childhood leukemia
Social History
• Lives with both parents
• No pets or smokers at home
Physical Exam
VS WNL
Gen awake, alert, no acute distress
HEENT PERRL, oropharynx clear, no LAD, TM’s
normal
Lungs clear to auscultation
Heart Normal S1/S2, no murmurs
Abdomen soft, nontender, no organomegaly
Ext L knee: (+) effusion, limited ROM secondary
to pain
R knee: limited ROM secondary to pain
B/L ankles: erythema over lateral malleoli, no
swelling, FROM
No nail changes
Skin multiple erythematous, pruritic papules on
back, buttocks with some excoriations
What are your differentials?
Differential Diagnoses
Viral Exanthems
Urticarial Vasculitis
Meningococcemia
Reactive Arthritis
Other drug reactions
Erythema Multiforme
Steven Johnson's Sydrome
Kawasaki's disease
Serum Sickness Rash
SJS rash
Meningococcemia Rash
Kawasaki
Labs
Parvovirus B19 IgG and IgM (normal)
ASLO normal (25)
Streptozyme negative
C4 28 C3 148
Lyme Ab titer 0.2 (normal)
CBC WBC 13.9 Hgb 12 Hct 35.4 platelets 429 N 52 L 43
Blood Culture negative
ESR 40
CRP 3.5
ua normal
Urine culture negative
Labs
Na 136 K hemolyzed Cl 102 HCO3 20 BUN 9 Creatinine 0.6
glucose 117 Ca 9.8
albumin 4.1 TP 6.7
ALT hemolyzed AST 11
Alk phos 145
TB 0.2 DB 0
Serum Sickness
First described by von Pirquet and Schick. They described an
illness that developed in some patients after they were given
horse serum antitoxin for diphtheria and Scarlet fever. The
illness developed a few weeks after administration of horse
serum antitoxin.
Cardinal features: rash, fever, and polyarthralgias or
polyarthritis, which begin 1-2 weeks after exposure to the
responsible agent.
Pathophysiology
Type III Hypersensitivity Reaction
1. Immune complex formation
2. Complement activation
3. Complement- independent mechanisms
Immune complexes in tissues can react directly with Fc gamma
receptors on neutrophils, mast cells, and phagocytes, leading
to release of cytokines, histamine, and other inflammatory
mediators even without complement.
Precipitin Curve
Serum-like sickness
May be caused by drugs, viral infections
Has different pathophysiology than serum sickness
Levels of circulating immune complexes and serum
complement are often unaffected
Commonly implicated drugs: Cefaclor Penicillin (amoxicillin)
Trimethoprim-sulfamethoxazole
Heterologous Proteins Causing
Serum Sickness
Microbial antitoxins
• Equine anti-diphtheria
• Equine or ovine anti-rabies
• Equine anti-botulinin toxin
Venom anti-toxins
• Equine, rabbit, ovine anti-snake venom
(crotalidae (pit vipers, rattlesnakes)
antivenin, micrurus (coral snake) antivenin)
• Equine anti-spider venom (lactrodectus)
antivenin
Heterologous Proteins Causing
Serum Sickness
Immunomodulators
• Equine or rabbit antithymocyte globulin
Murine antiCD3 (OKT3)
• Rituximab (murine/human chimeric antiCD20) Infliximab
• (murine/human chimeric anti-TNF alpha)
Alemtuzumab (humanized anti-CD52,
Campath)
Immunizations
• Rabies antigens (human diploid cell rabies
vaccine)
Cefaclor and Bactrim
Metabolites toxic to lymphocytes. The predisposing drug
metabolism is genetically influenced.
Penicillin
May be caused by drug-specific immune complexes, not
complexes with heterologous serum proteins.
Signs and Symptoms
Arthralgias
Lymphadenopathy
Urticarial rash
Fever, when present, is typically low-grade.
Acute onset of joint pain, often leading to inability to walk
Labs
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CBC
ESR, CRP
Urinalysis
Complement levels
If infectious etiology is to be ruled out,
cultures, titers should be obtained.
Treatment
Discontinuation of the offending agent
Supportive care
Antihistamines for urticaria
Nonsteroidal anti-inflammatory drugs (NSAIDs) for arthritis,
arthralgia, or both
Steroids (Prednisone or Methylprednisolone)- Patients with
higher fever (eg, temperature >38.5ºC), more severe arthritis and
arthralgias, or more extensive rashes including extensive vasculitic
rashes may be treated with short courses of glucocorticoids.
References
Brucculeri, M. et al. Serum sickness-like reaction associated
with cefazolin. BMC Clin Pharmacol. 2006; 6: 3.
Hay Jr., W. et al. Current Pediatric Diagnosis and Treatment,
15th ed. McGraw-Hill. 2001: pp. 958-960.
www.emedicine.com
www.uptodate.com
PREP Questions
• You have been asked by a local school to provide
recommendations about the use of self-injectable
epinephrine for anaphylaxis. The school supervisor is
concerned about the increased incidence of peanut and
tree nut food allergy. School officials have requested
that each child who has a diagnosis of "food allergy"
have two self-injectable epinephrine devices at the
school nurse's office.
Of the following, the BEST response regarding
anaphylaxis is that
A. A patient should not receive a second dose of
epinephrine unless a clinician is present
B. Epinephrine reaches higher peak plasma concentrations
if injected into the thigh rather than the arm
C. Families should keep one epinephrine autoinjector in
the car in case a reaction occurs after school
D. Skin manifestations (eg, flushing, itching, urticaria) are
rare in severe anaphylaxis
E. Subcutaneous injection of epinephrine is preferable to
intramuscular injection
In the past, outpatient administration of epinephrine was
subcutaneous, but research has demonstrated that
intramuscular injection, specifically in the thigh, is the
preferred route and location due to higher and faster peak
plasma concentration. If epinephrine is administered,
parents or school should call emergency services to
evaluate the child and transport him or her to the ER for
further evaluation. The effects of a single dose of
epinephrine typically last for 5 to 15 minutes; up to 20% of
individuals experiencing anaphylaxis may require a second
epinephrine dose. When symptoms persist, a second (or
third) dose should be administered, even if the parent or
school professional still is awaiting the ambulance.