Diagnosis of immediate hypersensitivity Flashcards
symptoms of systemic anaphylaxis
- caused by mast cell degranulation
- heart=increased capillary permeability and entry of fluid into tissues..swelling of tissues, tongue swelling, loss of blood pressure, reduced oxygen, irregular heartbeat, anaphylactic shock
- respiratory tract= contraction of smooth muscles, constriction of throat and airways, difficulty breathing and swallowing
- GI= constriction of smooth muscles, stomach cramps, vomiting, diarrhea
agents that cause anaphylaxis (Ige dependent)
-food
-milk-
medication
venom
latex
hormones
agents that cause anaphylaxis non Ige dependent, allergic
- immune aggregates (type II)= intravenous immunoglobulin, dextran
- cytotoxic( type III)= transfusion reactions to cellular elements (Igg , Igm)
agents that cause anaphylaxis ( non allergic non Ige)
- multimediator complement activation= radiocontrast media, ethylene oxide gas on dialysis tubing, protamine, Ace inhibitor administered during renal dialysis
- nonspecific degranulation of mast cells and basophils= opiates,idiopathic,physical features(exercise,temp)
Signs of anaphylaxis
erythema pruritus angiodema bronchospasm hypotension hyperperistalsis arrythmias nausea vomiting lightheadedness headache flushing geeling of impending doom
Atopy
- # of patients w/history of allergy increase percent of children with atopy
- as Ige serum levels increase so does atopy
- sensitization occurring with casual exposure to specific antigens
- predisposition to allergic symptoms (eczema, allergic rhinitis,extrinsic asthma, food allergy AKA allergic tetrad)
most common symptom of anaphylaxis
- urticaria or angiodema and flush are most common, followed by respiratory
- cutaneous manifestations may be delayed or absent
- more rapid the onset , more serious
- signs and symptom w/in 5-10 minutes but may not develop for hours
- asthma results in flattening of diaphram..can treat with omm
diagnostic tests used for hypersensitivity
-lab test: cbc, nasal secretions,stool
-in vivo test: respiratory test and
skin test->scratch,intracutaneous,patch testing (type IV delayed involving no skin puncturing), prausnitz-kustner(no longer used due to risk of blood borne illness)
- in vitro test: RIST&RAST
- the higher the number on rast test yje stronger the allergic response (based on Ige levels)
sufficient diagnostic test for allergy
history
physical exam
selected skin tests
elimination and oral challenge
immediate intervention of anaphylaxis
- assess airway ,breathing circulation
- administer EPI, repeat as necessary
- IM into anterolateral thigh produces higher rapid peak
- good for moderate or severe ANA
general measures for anaphylaxis
- place in recumbant positions nd elevate lower extremities
- maintain airways
- O2 6-8 liters
- if severe hypotension give volume expander colloid solution
- venous tourniquet above reaction site
specific measures that depend on scenario for anaphylaxis
- aqueous EPI at reaction site
- diphemhydramine in divided doses orally or IV (max 200 for children and 400 for adults)
- ranitidine
- bronchospasm nebulized albuterol
- refractory hypotension give dopamine
rapid response sequence
call for help position patient tourniquet epinephrine oxygen fluid antihistamine vasopressor bronchodilator steroids transport to hospital via ambulance
angiodema
- well demarcated non pitting edema
- caused by same thing as urticaria
- occurs deeper in dermis and subcutaneous tissue
- face tongue lips most commonly affected
- may cause life threatening respiratory distress if larynx involved
classification of angioedema
hereditary:
type 1-C1 esterade inhibitor deficiency
type 2- functional abnormality of C1 esterase inhibitor
acquired: idiopathic Ige mediated non Ige mediated systemic physical other
TREATMENT DIFFERENT FOR HEREDITARY VS ACQUIRED
