Urticaria, Angioedema, Anaphylaxis by qga16183

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									Urticaria, Angioedema, &
Anaphylaxis

    Noel Mensah-Bonsu, MD
Case 1

 7 yo F presents w/ a red itchy rash after
 playing outside in the grass all day. Parents
 note that she must have been bitten by
 numerous mosquitos. The individual ‘welts’
 are on her trunk and extremities and she
 complains of itchiness. She has received no
 medications for them.
Case 1 Questions

 Important History?
 Differential diagnosis?
 Mechanism of injury?
 Evaluation for acute vs. chronic urticaria?
 Treatment?
Important History?

 Infectious sx, abx, NSAIDS, arthralgias
 Are symptoms c/w urticaria?
   Raised, red, itchy, mobile, resolve in 24 hrs
 Is angioedema occurring?
 Length of symptoms?
 Hx atopy?
Differential Diagnosis acute vs. chronic?

 Acute urticaria
   Erythema multiforme, marginatum, infectiosum
   Drug eruption, serum sickness
   Insect bites
 Chronic urticaria
   urticarial vasculitis (SLE, Sjogren’s syndrome)
   cryoglobulinemia (Hep C), hepatitis A/B, parasitic
   infection, urticaria pigmentosa (mastocytosis)
Mechanism of tissue injury?
 Urticaria results from release of inflammatory
 mediators and increased capillary permeability
 which causes edema of the superficial dermis
   IgE mediated
     Stinging insects, foods, additives, aeroallergens, contact
     allergens, parasitic infxns, blood products
   Direct mast cell activation (non-IgE)
     Narcotics, muscle relaxants, vancomycin, radiocontract
     medium
   Complement-mediated
     Viral/bacterial infections, serum sickness
Evaluation?

 Acute
   Up to 80% probably infectious
 Chronic
   CBC, ESR, LFTs, TSH, antithyroid antibodies
     30-50% autoimmune, autologous serum skin test
   Food allergy testing generally not helpful w/o
   clinical history
   Abnormal labs 21% of the time
Treatment?

 Antihistamine
  2nd generation H1: loratidine, cetirizine
  1st generation H1: diphenhydramine, hydroxyzine
  Corticosteroids rarely necessary
  H2 receptor antagonists: ranitidine, famotidine
  Others
    leukotriene receptor antagonists, thyroxine,
    cyclosporine, dapsone, doxepin
Case 2

 16 yo M w/ a dozen episodes of lip and facial
 swelling in the last year. He recalls that
 during high school football, his hands and
 elbows often swelled after getting tackled,
 although he attributed the swelling to trauma.
 Recently, he also has experienced episodes
 of abdominal pain.
Case 2 Questions

 Important History?
 Differential diagnosis of facial edema?
 Mechanism/pathogenesis?
 Evaluation?
 Treatment?
Important History:

 Triggers?
 Hives/urticaria?
 Recurrent?
 Meds?
 Family hx?
 Atopy?
Differential Diagnosis of facial edema?
 Angioedema
 Allergic contact dermatitis
 Cellulitis
 Lymphedema
 Autoimmune disease
 Hypothyroidism
 SVC syndrome
 Mastocytosis
Mechanisms?
 Angioedema results from mast cell activation
 & degranulation w/ release of inflammatory
 mediators causing ↑ vascular permeability in
 the deep layers of the dermis and the
 subcutaneous tissue.
  Mast cell-mediated
    Allergic, autoimmune, direct mast cell release
  Kinin-related
    ACE inhibitor, angiotensin II receptor blocker, C1
    inhibitor deficiency or dysfunction
  Unknown
    Aspirin, NSAIDS, infections
Etiology of Angioedema

 Hereditary
 Acquired
  Allergic
  Idiopathic
 Medication-induced
  ACE inhibitors, ARBs
Evaluation?

 Workup often unrevealing (90%)
 Based on history and physical exam
 Labs
   C4…if low, check C1 inhibitor levels
Treatment:

 Anaphylaxis      epinephrine
 Acute allergic angioedema
  Antihistamine
  Corticosteroids
 Hereditary or Acquired angioedema
  Dental/oral surgery prophylaxis w/ androgen
  C1 inhibitor concentrate
  FFP
 Medication-induced…d/c meds
Case 3

 12 yo M brought to ER w/ acute onset of
 facial swelling. Fifteen minutes later, he
 began to complain of SOB. His parents
 observed him to have some difficulty
 breathing. He also said that he felt very weak
 and dizzy. His parents brought him
 immediately to the ED.
Case 3 Questions

 Differential diagnosis?
 What are the symptoms of anaphylaxis?
 Mechanism?
 Common causes?
 Evaluation?
 Management?
Differential Diagnosis?

 Anaphylaxis
 Severe asthma
 Systemic mastocytosis
 Carcinoid syndrome
 Vasovagal response
 Drug overdose
 Scombroidosis
Symptoms of Anaphylaxis?

 Skin-mucous membrane involvement
  Hives, pruritis, flushing, swollen lips/tongue/uvula
 Respiratory compromise
  Dyspnea, wheeze, stridor, hypoxemia
 Persistent GI symptoms
  Crampy abdominal pain, vomiting
 Cardiovascular: BP or symptoms associated
  Syncope, incontinence, collapse
Mechanism?
             Action                                 Mediator
             Vasodilation, increased                Histamine
             vascular permeability                  PAF
                                                    Leukotrienes C4 , D4 , E4
                                                    Neutral proteases that activate
                                                    complement/kinins
                                                    Prostaglandin D2
             Smooth muscle spasm                    Leukotrienes C4 , D4 , E4
                                                    Histamine
                                                    Prostaglandins
                                                    PAF
             Cellular infiltration                  Cytokines, e.g., TNF
                                                    Leukotriene B4
                                                    Eosinophil and neutrophil
             chemotactic
                                                    factors
                                                    PAF

             PAF, platelet-activating factor; TNF, tumor necrosis factor.
Anaphylaxis                    Anapylactoid
(IgE mediated)                 (not IgE mediated)

  Food
                                  Direct release of mast cell mediators
     Tree nuts, peanuts
                                     Drugs (opiates, NMBs)
     Grains
                                     Hypertonic solutions (mannitol)
     Eggs & dairy
                                     Exercise
     Shellfish
                                  Immune complex mediated
  Venoms
                                     Blood products
     Hymenoptera
                                     Gamma globulin
     Snake, Fire ant
                                     Antisera
  Therapeutic Agents                 Dialysis membranes
     Antibiotics
                                  Arachadonic acid metab modulators
     Vaccines
                                     NSAIDs, ASA
  Human proteins                     Tartrazine
     Hormones (insulin)
                                  Unknown mechanism
     Enzymes (streptokinase)
                                     Radiocontrast media
     Blood & blood products
                                     Preservatives
  Latex
Anaphylaxis                    Anapylactoid
(IgE mediated)                 (not IgE mediated)

  Food                           Direct release of mast cell mediators
     Tree nuts, peanuts             Drugs (opiates, NMBs)
     Grains                         Hypertonic solutions (mannitol)
     Eggs & dairy                   Exercise
     Shellfish                   Immune complex mediated
  Venoms                            Blood products
     Hymenoptera                    Gamma globulin
     Snake, Fire ant                Antisera
  Therapeutic Agents                Dialysis membranes
     Antibiotics                 Arachadonic acid metab modulators
     Vaccines                       NSAIDs, ASA
  Human proteins                    Tartrazine
     Hormones (insulin)          Unknown mechanism
     Enzymes (streptokinase)        Radiocontrast media
     Blood & blood products         Preservatives
  Latex
Evaluation?

 ABG, CXR
 Acute
   Tryptase, histamine
 Long-term
   Referral to an allergist-immunologist for further
   evaluation, skin testing, RAST
   Allergen education and avoidance.
Management?
 A/B/Cs
 Epinephrine
 Antihistamines?
 Corticosteroids
 Bronchodilators
 Consider glucagon for patients on beta-
 blockers
 Fluid resuscitation
 Vasopressors
Urticaria, Angioedema and
Anaphylaxis

    NMB
Common theme?

 Mast cell degranulation can result in different
 clinical syndromes…
 Anaphylaxis may occur w/ or w/o
 angioedema and urticaria
 Treatment often w/ antihistamines,
 steroids…for anaphylaxis, always
 epinephrine first!
Question 1

 A previously healthy 5 yo F is brought to the ED soon after
 being stung by a “bee.” You note several raised, white-red,
 intensely pruritic areas on her trunk; slight swelling of her lips
 and eyelids; and wheezing on auscultation of her chest. The
 first drug she should receive is:

   A. Oral 1st generation antihistamine
   B. Oral leukotriene receptor antagonist
   C. Oral 2nd generation antihistamine
   D. Parenteral epinephrine
   E. Parenteral glucocorticosteroid
Question 2

 Among the following, life-threatening
 anaphylaxis in children occurs most often as
 a result of exposure to :

  A. Exercise
  B. Foods
  C. Latex
  D. Perioperative drugs
  E. Vaccines
Question 3
 A 10-year-old boy presents to the clinic for evaluation of an insect sting
 reaction. He was playing in his yard yesterday when he was stung on the
 right forearm by a wasp. His parents immediately placed ice over the area,
 but they are worried because when the child awoke today, the redness that
 initially was localized to the sting site had extended to involve his entire right
 forearm. The boy denies fever, chills, nausea, vomiting, or difficulty
 breathing. His vital signs on physical examination are normal. His right
 forearm is diffusely erythematous and warm to palpation but not tender.

 Of the following, this child's insect sting reaction is BEST characterized as

    A. Cellulitis
    B. Large local reaction
    C. Normal reaction
    D. Systemic anaphylaxis
    E. Toxic reaction
Question 4
 You are performing a presedation physical examination in a 3-year-old
 female who is scheduled to have a repeat computed tomography (CT) scan
 with contrast. The mother mentions that her daughter experienced diffuse
 hives and facial swelling 10 minutes after the contrast administration during
 her first CT.
 Of the following, the BEST way to prevent future contrast reactions is to:


    administer 1 L intravenous normal saline prior to the procedure
    perform desensitization to contrast
    provide pretreatment with oral antihistamines and steroids
    use a high-osmolar contrast agent
    use a contrast agent with low iodine content
Take Home

 Anaphylaxis      epinephrine
 Epi pen = 0.3mg epinephrine
 Epi pen junior = 0.15mg epinephrine
 Evaluation is based on history and physical
 exam!

								
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