Genetic predisposition to IgE mediated immune disease

• allergic rhinitis
• atopic dermatitis
• asthma

What type of hypersensitivity rxn?

• <30min, 2-12hrs
• Ab: IgE
• Antigen: pollen, food, drugs, venom
• Mediator: histamine, tryptase, leukotrienes
• Ex: anaphylaxis, urticaria, rhinitis, asthma

Type 1: Anaphylactic, immediate, late phase

What type of hypersensitivity rxn?

• Ab: IgG, IgM, IgA
• Antigen: Rbcs, platelets
• Mediator: complement
• Ex: Rh, hemolytic anemia

Type II: cytotoxic antibody

What type of hypersensitivity rxn?

• 4-8hrs
• Ab: Antigen w/Ab
• Antigen: blood vessels, liver, spleen
• Mediator: complement anaphylatoxin
• Ex: serum sickness

Type III: Immune complex reactions

What type of hypersensitivity rxn?

• 24-48hr
• Ab: lymphocytes
• Antigen: TB
• Mediator: cytokines
• Ex: TB skin test

Type IV: delayed type

What type of hypersensitivity rxn?

• Antigen bind IgE on mast cells, basophils
• causes release of preformed mediators
• late phase from recruitment of other inflam cells

Type I

Atopy risk factors - Family hx

1 parent: risk __% to child

2 parents: risk __% to child

• similar dz runs in family but at risk for all 3 of triad
• personal hx of one dz, higher risk of other 2

1 - 25%

2 - 50-75%

Allergic rhinitis m/c common in kids, adolescents

Rare in children ___

Seasonal allergic rhinitis seen in children ___

<6 mos

>3 yo

Eyes: allergic shiners, Dennie-Morgan folds, cobblestoning of conjuctiva, conjunctival injection

Nose: transverse nasal crease (nasal salute), nasal flaring, pale, boggy turbinates, discharge, polyps

Mouth: tonsillar hypertrophy, postnasal drip

What's the best test for detecting presence of allergen specific IgE?

How does it work?

Skin test

• allergen interacts with IgE causing histamine release
• histamine release causes wheal and flare

at least 1 weeks

What type of patients cannot have skin testing done?

What is done instead?

• pts with dermatographism or extensive dermatitis
• pts who can't stop antihistamines, antidepressants, or other meds that confound testing
• children <1 yo

they must undergo serum testing (RAST)

*presence of specific IgE antibodies alone is not diagnostic. indicates sensitization not allergic rxn*

Intranasal corticosteroids

- Fluticasone (Flonase)

- Mometasone (Nasonex)

1st gen: Diphenhydramine (Benadryl), Hydroxyzine (Atarax, Vistaril)

2nd gen: Cetirizine (Zyrtec), Loratadine (Claritin), Fexofenadine (Allegra)

IgG, IgE

Clinical manifestations of anaphylaxis

1. Cutaneous
2. Respiratory
3. Cardiovascular
4. Gastrointestinal

1. pruritus, erythema, urticaria, angioedema
2. sneezing, rhinorrhea, edema of upper airway, tachypnea, apnea, bronchospasm
3. tachycardia, dysrhythmia, cardiovascular collapse
4. nausea, vomiting, diarrhea

• maintain airway
• ephinephrine subq or IM
• liquid diphenhydramine (Benadryl)
• H2 blocker (ranitidine)
• steroids (prednisone, prednisolone)

Atopic dermatitis / Eczema

Describe the 3 stages of eczema

1. Acute
2. Subacute
3. Chronic

1. intensely pruritic erythematous papules over reddened skin
2. excoriated scaling erythematous papules or plaques.
3. thickened skin with lichenification

acute

itchy macular areas, blanchable urticaria, angioedema

Asthma

Childhood: M > F

Young adulthood: M = F

>40 yo: F > M

1. mucosal edema
2. smooth muscle contraction
3. production of mucus

NSAIDs, Aspirin, Beta blocker

tired, overly lethargic child

• mental status
• can they talk? ABCs
• position (tripod)
• color - cyanosis?
• diaphoresis
• body habitus
• odor - smoke?
• distress

• tracheal tugging
• masses
• tracheal deviation (tension pneumo)
• JVD

LOOK: count the rate, AP diameter, retractions, abd breathing

LISTEN: prolonged exp phase, air movement, crackles, wheezes, no wheezes?

FEEL: percussion - hyper-resonant

hyperinflation

• non-specific
• hyperinflation, flattening of diaphragm (should be 7-8 ribs showing)
• peribronchial thickening
• look for infiltrate, foreign body, pneumothorax

What asthma severity?

• symptoms <2 days/wk
• wake at night <2 nights/mo
• use SABA <2 days/wk
• does not interfere w/nml functioning

intermittent

What asthma severity?

• symptoms >2 days/wk but not daily
• wake at night 3-4 nights/mo
• use SABA >2 days /wk but not daily and not >1x/day
• minor interference in normal functioning

Mild persistant

What asthma severity?

• symptoms daily
• wake at night >1x wk but not nightly
• use SABA daily
• some limitations in activities

Moderate persistant

What asthma severity?

• symptoms throughout the day
• wake every night
• use SABA several times/day
• very limiting on activities

Severe persistant

1. routine monitoring of symptoms and lung fxn
2. pt education to create partnership
3. controlling environmental factors and co-morbid conditions that contribute to severity
4. pharmacologic therapy

How do you treat asthma?

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

1. SABA PRN
2. low-dose ICS
3. low-dose ICS + LABA or med-dose ICS
4. med-dose ICS + LABA
5. high-dose ICS + LABA and consider omalizumab for pts w/allergies
6. high-dose ICS + LABA + oral corticosteroids and consider omalizumab for pts w/allergies

Bronchodilators

1. Name 2 SABA
2. Name 2 LABA
3. Name 1 Anticholinergic

1. Albuterol, Levalbuterol
2. Salmeterol (Serevent), Formoterol (Foradil) *used only in combo w/inhaled corticosteroids*
3. Ipratropium (Atrovent)

inhaled corticosteroids

Heliox - inhaled gas composed of helium and oxygen

omalizumab (Xolair)

IgG mab binds to unbound IgE and prevents the binding of IgE to the high-affinity IgE receptor on the surface of mast cells and basophils

• oxygen
• nebulized albuterol (<20kg = 2.5mg; >20kg = 5m)
• asthma pathway: albuterol +/- Atrovent neb x3
• prednisone (2mg/kg up to 60mg)

• use of 2 or more beta-agonist inhalers / month
• previous life threatening attacks, visits to ER
• hospitalization for asthma in past year
• poor perception of hypoxia or airway obstruction
• large circadian variation in lung function
• male sex
• low socioeconomic status or education
• psychosocial disturbances