Allergy and Immunology Flashcards
Recurrent bacterial infections, X-linked inheritence, small tonsils
Bruton or X-linked agammaglobulinemia
Bruton agamaglobulinemia genetics
- X linked
- BTK gene
- Complete defect in B cell production
Bruton agamaglobulinemia symptoms
- Bacterial infections (respiratory and skin) starting around 6 months of age (protected by maternal antibodies prior to that)
- Small tonsils
- Require life long IVIG replacement or stem cell transplant
Atopic march order in kids
- Atopic dermatitis in infants
- Allergic rhinitis in children
- Asthma in children/adolescents
Most important risk factor for developing atopic disease
Parent with atopic disease
50% risk if 1 parent, 70% risk if both
Asthma epidemiology
- Mortality is increasing
- MC in boys, African Americans, and Hispanic children
Spirometry measurements
- Inspiratory and expiratory flow rate
- Decreased FEV1 in asthma
- It DOES NOT measure total lung capacity or residual volume
Asthma symptoms: symptoms and albuterol < 2 days/week, zero nighttime awakenings
Intermittent
Tx: SABA PRN
Asthma symptoms: symptoms and albuterol > 2 days/week but not daily, nighttime symptoms 1-2 times per month
Mild persistent
Tx: Low dose inhaled steroids, can add leukotriene inhibitor
Asthma symptoms: symptoms and albuterol daily, nighttime 3-4 times per month
Moderate persistent
Tx: Medium dose inhaled steroids, can add LABA or montelukast
Asthma symptoms: symptoms all day long, albuterol multiple times a day, night symptoms more than once a week
Severe persistent
Tx: High dose inhaled steroids plus LABA, montelukast
Side effects of beta blockers
Tachycardia, tremors, hypokalemia, hyperglycemia
How do inhaled steroids help asthma
Decrease bronchial inflammation and also reduce bronchial hyperresponsiveness
Signs of hypercapnia in asthma
- Fatigue, CO2 retention
- Agitation, flushing, mental status change, headache, tachycardia
Symptoms of poorly controlled asthma
Rule of 2s:
- Symptoms 2 or more days a week
- Waking up at night 2 times a month
- Albuterol 2 or more times a week
- Steroids more than 2 times a year
Four types of allergic reactions
- Type 1 = Anaphylactic (A) - IgE mediated
- Type 2 = Mediated by AntiBodies (B)
- Type 3 = Immune complex
- Type 4 = Delayed hypersensitivity (poison ivy)
What interferes with skin allergy testing
Any antihistamine use will interfere with the results of skin testing but not IgE testing
- Contraindications to skin testing: urticaria, mastocystosis (skin conditions), high anaphylactic risk (poorly controlled asthma), recent anaphylactic event
When is in vitro IgE allergy testing preferred
- Kids on chronic antihistamines (it doesn’t affect the testing)
- Children with extensive eczema or skin infections (limited area to do skin testing)
- Limitations: higher cost and higher false positive rate
Penicillin allergy testing
- The only antibiotic that can be skin/IgE tested
- IgE mediated reaction starts within 24 hours of penicillin exposure
- Chance of having reaction to cephalosporins is less than 10%
Non allergic rhinitis with eosinophilia syndrome
Allergy symptoms and eosinophils on nasal smear but skin tests are negative and serum IgE levels would be normal
Symptoms of infectious rhinitis
Presents in younger children with nasal congestion worse in the winter
Symptoms of vasomotor rhinitis
Congestion, rhinorrhea, post-nasal drainage without any specific trigger
- But can be associated with emotions, pollution, cold drafts, rapid temperature changes, or changes in humidity
Symptoms of rhinitis medicamentosa
- Rebound reaction to adrenergic nose drops (leads to severe nasal congestion)
Symptoms of aspirin triad
- Nasal polyps
- Aspirin intolerance
- Asthma
- Have chronic nasal congestion and anosmia
Nasal complication of cocaine abuse
Nasal septum perforation
At what age can seasonal allergic rhinitis be diagnosed
Not until age 3, requires repeated exposure
Who needs to be sent for food allergy testing
Kids with severe eczema and persistent asthma
Most common childhood allergies
Milk, eggs, peanuts, tree nuts, soybeans, wheat, fish
- IgE mediated allergy reactions occur within minutes, food poisoning happens 6 or more hours after
At what age are most food allergies outgrown
Age 5 - milk, egg, and soy are usually outgrown (the others are not)
Treatment of anaphylaxis
- Epinephrine 0.01 mg/kg 1:1,000 IM every 15 minutes
- 0.3 mg for patients > 30 kg, 0.15 mg for patients < 30 kg
Chronic urticaria cause and treatment
- If > 6 weeks then it is chronic
- Most likely cause is food
- Treatment: antihistamines (2nd or 3rd generation) for long term, can use benadryl in short term
- Allergy testing has no role, no need for chronic steroids
Cause of reaction to contrast
Osmolality-hypertonicity reaction that triggers degranulation of mast cells and basophils with release of mediators
Allergic reaction to stings symptoms
- Localized non-systemic symptoms (even hives) don’t require allergy testing
- Triad of systemic reactions: hypotension, wheezing, laryngeal edema
- Tx: remove stinger as fast as possible
- If systemic reaction, need to have epi-pen and if life threatening reaction need treated with allergy shots
Normal amount of infections in childhood
It’s okay for a kid to have one infection a month especially if self limited GI or respiratory infections –> don’t need immunodeficiency workup
Chronic Granulomatous Disease cause
- Phagocytic dysfunction
- Can’t undergo respiratory burst needed to kill bacteria and fungi (get infected with those)
- 2/3 are X-linked, 1/3 are autosomal recessive
CGD symptoms
- Bacterial infections, present in the first 5 years of life
- MC infections are deep abscesses, pneumonia, lymphadenitis, osteomyelitis, and systemic infections
- S. aureus, B. cepacia, Serratia, and fungi
CGD diagnosis and treatment
- Nitroblue tetraolium test (NBG) - assays the phagocytic oxidase activity
- Okay to get live viral vaccines but not bacterial
- Ppx with bactrim and itraconazole
Leukocyte adhesion deficiency cause
- Defect in chemotaxis (WBCs can’t get to where they need to go or adhere to the endothelium)
LAD symptoms
- High WBC count
- Perirectal abscess, indolent skin infections, omphalitis
- Infections have NO PUS and minimal inflammation, delayed wound healing
- Can present with delayed umbilical separation
LAD diagnosis and treatment
- Dx is flow cytometry
- Tx: bone marrow and stem cell transplantation
Chediak-Higashi syndrome cause
- WBCs contain lysosomal granules and have abnormal chemotaxis
- Autosomal recessive
Chediak-Higashi syndrome symptoms
Frequent infections, easy bruisability, oculocutaneous albinism
- Infections occur in the lungs and skin
- MC pathogens are Staph aureus, strep pyogenes, pneumococcus
Chediak-Higashi syndrome diagnosis and treatment
- Diagnose with giant granules in neutrophils on blood smear
- Tx with bone marrow transplant
Humoral immune deficiency general symptoms
- Antibody deficiencies are the most common
- Recurrent sinopulmonary infections with ENCAPSULATED BACTERIA
- Symptoms begin at 4-6 months of age due to initial protection with maternal antibodies
- NO LIVE VACCINES
IgA deficiency symptoms
- MC primary immunodeficiency, over 80% are asymptomatic
- Recurrent sinopulmonary infections
- NOT an indication for IVIG replacement
Bruton’s X-linked agammaglobulinemia symptoms
- Mostly affects B cells (T cell count may be elevated)
- Serum levels of IgG, IgA, IgM, and IgE are very low with small lymphoid tissue and small spleen
- Baby boy with recurrent infections with encapsulated pyogenic bacteria (Strep pneumo and H flu)
- Require IVIG
- Risk for bronchiectasis and chronic pulmonary insufficiency
CVID symptoms
- MC clinically significant immunodeficiency
- B lymphocytes don’t differentiate into plasma cells so deficiency of immunoglobulin subtypes
- T cells are also often affected
- HAVE NORMAL CBC
- Recurrent respiratory and GI infections, also risk for recurrent herpes/zoster infections
- Associated with autoimmune diseases and increased risk of lymphoma
- Require IVIG
X-linked Hyper IgM Syndrome
- Disruption of B cell differentiation, can’t convert IgM to IgG
- Male infant age 6-12 months with frequent otitis and sinopulmonary infections as well as diarrhea
- LYMPHOID HYPERTROPHY
- Think of this with opportunistic infections (PCP with no HIV)
- Labs: low IgG, IgA, IgE with high IgM
- Tx with IVIG
Job Syndrome (Hyper IgE) symptoms
- Eosinophilia, Eczema (recurrent skin infections), elevated IgE
- Staph aureus, sinopulmonary infections, chronic thrush, abnormal facies, multiple fractures, skeletal abnormalities
- Can be mistaken for atopic dermatitis or Wiskott-Aldrich
- Tx with steroids and antibiotics
Transient hypogammaglobulinemia of infancy
- Decreased T helper function leads to low IgG and IgA
- Manifests by 6 months or so and outgrow by 3-6 years of age
Cellular immune deficiency general rules
- Present with opportunistic infections
- Low lymphocyte count
- Don’t give live vaccines
SCID symptoms
- Complete absence of B and T cell function
- Present in first 3 months of life with failure to thrive, chronic diarrhea, recurrent opportunistic infections
- Low WBC, complete abscence of T cell function
- Tx: supportive but need BMT
Wiskott Aldrich Syndrome symptoms
- X linked (presents in males)
- Triad is: eczema, thrombocytopenia (unusual bleeding), cellular immunodeficiency
- Low platelet count with SMALL PLATELETS
- Sinopulmonary infections with encapsulated bacteria –> opportunistic infections with PCP and herpes
- High rate of lymphoma (MCC death)
- Tx with BMT or stem cells
Complement deficiency symptoms and management
- C1-C4 deficiency: recurrent sinopulmonary infections due to encapsulated bacteria
- C5-C9 deficiency: recurrent Neisseria infections and increased risk of meningitis
- Autosomal recessive
- Screen with CH50 assay
- Okay to give all vaccines, no therapy
Humoral vs Cellular immunodeficiency symptoms
- Humoral (B cell): present AFTER 6 months, sinopulmonary and GI tract infections, test for quantitative immune globulins
- Cellular (T cell): sick AT BIRTH, severe infections, test for lymphocyte subset analysis via flow cytometry
Symptoms of systemic mastocytosis
- Darier sign (formation of a wheal upon gentle stroking of reddish-brown macules on the skin)
- GI ulcers
- Small itchy bumps on skin
Immunodeficiency with increased risk of infections from giardia
- Selective IgA deficiency
Immunodeficiency with increased risk of anaphylaxis after blood transfusion
- Selective IgA deficiency
What type of reaction can occur after initial exposure to a foreign antigen and doesn’t require prior exposures
Serum sickness
Risk factors for persistent asthma
Early RSV infection, maternal asthma, smoke exposure, elevated IgE, atopic disease
