MDT's Immune System Flashcards
What is an allergy?
Immunologically mediated hypersensitivity reaction to a foreign antigen manifested by tissue inflammation and organ dysfunction
What does the clinical expression of allergic disease depend on?
- Prior immunologic responsiveness
- Antigen exposure
- Genetically influenced host factors
What are the two time frames for allergic reactions?
- Immediate (within 60 minutes)
- Delayed (appearing hours/weeks after exposure)
What is anaphylaxis?
Most serious and potentially life-threatening manifestation of mast cell and basophil mediator release
How is anaphylaxis clinically defined?
- Acute onset of illness involving skin/mucosal tissue and either respiratory compromise or hypotension ( systolic <90mmHg or 30% drop)
- Likely allergen exposure followed by 2+ of the following:
- Skin/mucosal involvement
- Respiratory compromise
- Hypotension
- Persistent GI Sx
Timeframe for Food allergy reaction?
- Within 2 hours
- Much less common in adults
What are the most common anaphylactic food reactions?
- Shellfish
- Peanuts
- Tree nuts
Diagnosis of food allergies relies on?
- History
- Skin tests
- Specific IgE tests
Symptoms/Physical findings of allergic reaction?
- Usually within 30 minutes
- Skin manifestations such as Urticaria, flushing, blotchy rashes
- Respiratory distress: wheezing, stridor
- GI Sx’s: cramping, emesis, diarrhea
- Hypotension
Treatment of allergic reaction?
- Epinephrine
- Oxygen
- IV Fluids (NS)
- Airway management
- Antihistamines (Benadryl, losartan, Claritin)
Initial care/follow up for allergic reation?
- Monitor for delayed repeat anaphylaxis (can be up to 4 hours)
- Referral to allergist:
- Concern for future reactions
- New/unexplained onset
What is Urticaria?
- Formation of allergen mediated rash
- Evanescent wheals/hives
- Intense itching
- Special features
- Acute, but self-limited (1-2 weeks)
What special features are seen with urticaria?
- Dermatographism
- Cholinergic urticaria
- Solar urticaria
- Cold urticaria
What is chronic urticaria?
Episodes lasting longer than 6 weeks
- may have autoimmune basis
Symptoms/physical findings of Urticaria?
- Lesions are itchy, red swellings (mm to cm)
- Morphology of lesions may vary over minutes to hours
- Lesions last <24hrs, often only 2-4 hrs
Treatment of Urticaria?
- Antihistamines
- Detailed Hx for tailored treatments
Complications of urticaria?
- Cellulitis from itching
- Anaphylaxis
- Asthma attacks
What is angioedema?
Swelling of vascular tissue involving deeper subcutaneous tissue with swelling of the lips, eyelids, palms, soles, and genitalia
Overview of angioedema?
- Allergen mediated (usually food allergy)
- Can be hereditary
- Urticaria is not part of the syndrome
- Laryngeal angioedema can be life-threatening during anaphylaxis
Triggers for Angioedema?
- NSAIDS
- ACE inhibitors
- Estrogens
- ASA
- CCB
- Amiodarone
Treatment of angioedema?
- May need to intubate if involving mouth, face, or airway
- For anaphylaxis: Epinephrine, Antihistamines, Steroids
- Stop offending agent
What is Systemic Lupus Erythematosus?
- Inflammatory autoimmune disorder characterized by autoantibodies to nuclear agents
- Can affect multiple organ systems
- Marked by spontaneous remission and relapses
- Occurs mainly in young women, 85%
- Joint symptoms in 90%
Symptoms/physical findings Systemic Lupus Erythematosus?
- Systemic features (fever, malaise, anorexia, weight loss)
- Skin lesions
- Alopecia
- Joint symptoms (w/ or w/out synovitis)
- Ocular manifestations
- Neurological complications
Labs/Studies/EKG for Systemic Lupus Erythematosus?
- Antinuclear antibody tests
- Sedimentation rate and CRP for inflammation
- Can see anemia/thrombocytopenia
- Elevated LFT’s, BUN/Creatinine
