Allergy/Immunology Flashcards
What is required to be considered “high risk” for allergic disease?
- Personal history OR 1˚ relative with atophy
- Food allergy
- Allergic rhinitis
- Asthma
- Eczema
When should solids be introduced for average risk vs high-risk allergic children?
When introducing allergenic foods, what 2 things would you advise parents to do?
- Average risk = 6 months
- High-risk = 4-6 months
Introducing Allergenic foods
- Introduce one at a time, without unnessary delay between each food (1-2 days)
- If well tolerated, offer it a few times a week to maintain tolerance
- If adverse reaction observed, consult with PCP about next steps or if signs of anaphylaxis go to ED.
List 5 common food allergens
- Cow’s milk
- Egg
- Peanuts
- Tree nuts
- Fish
- Shellfish
- Wheat
- Soy
What type of immunodeficiencies present with sinopulmonary infections?
- B cell defects (ie. IgA deficiency, CVID, Agammaglobulinemia)
- T cell defects (ie. SCID, DiGeorge, Ataxia-Telangiectasia, APECED)
Other DDx:
- Primary ciliary dyskinesia
- BPD/CLD
- Cystic fibrosis
- Anatomic defect (ie. CCAM)
- Allergic rhinitis
- Social factors (ie. smoking, daycare, older siblings, etc)
- Secondary immunodeficiency (ie. immunosuppression, nephrotic syndrome, protein losing enteropathy, HIV, malnutrition, T21, malignancy)
List 4 immunocompromised medical conditons
- Post-HSCT (within 2y or still taking immunosuppressive drugs)
- Solid-organ transplant (lung, heart, kidney, liver, pancreas)
- Malignancy: current or recently treated
- Aplastic anemia
- Asplenia/functional asplenia
- HIV (CD4 <5yo: <15%; ≥5yo: <200)
- SCID
- Taking the following medications
- Chemotherapy
- High-dose corticosteroids (>2mg/kg for ≥2wks)
- Biologics
- Antimetabolites (e.g. azathioprine)
- Transplant-related immunosuppressive drugs (e.g. cyclosporine, tacrolimus, sirolimus, MMF)
Which 2 organisms are asplenic individuals at increased risk of contracting?
Which vaccine preventable organisms?
Which 3 viruses is an immunocompromised individual at highest risk of contracting?
- Salmonella
- Capnocytophaga
- (also malaria)
Vaccine preventable:
- Strep pneumo (PCV13, PPV23)
- Neisseria meningitidis (Menactra ACYW, Bexsero Men B)
- H. influenza
Viruses
- Adenovirus
- RSV
- Influenza
What is the general work up for Immunodeficiencies?
General screening lab work for immune deficiency:
- CBC with differential –> To evaluate for quantitative deficiency (ex. Lymphopenia, etc)
- Lymphocyte subsets
- CD3 T cells
- CD4 T cells
- CD8 T cells
- B cells
- NK Cells
- Immunoglobulin levels
- IgG, IgA, IgM, IgE
- Vaccination response:
- Tetanus, diphtheria, pneumococcal
- CH50 –> For complement disorders
What are the categories of Immunodeficiencies? Give examples.
How do they present?
What type of immune deficiency presents with recurrent lymphadenitis, bacterial abscesses, recurrent osteomyelitis (usually staph aureus), and Crohn’s like illness?
Chronic Granulomatous Disease
- Phagocytic defect (neutrophils can’t breakdown catalase-positive organisms)
- X-linked recessive
- Diagnosis: Nitroblue tetrazolium dye test, dihydrohodamine test
- Treatment (IgG, abscess drainage and HSCT = definitive)
What type of immunodeficiency presents with angioedema, recurrent pyogenic infections with encapsulated organisms (esp Neisseria), autoimmune disease (ie. SLE) and chronic nephritis?
Complement deficiencies
- Classical complement deficiencies = Presents with recurrent infections with encapsulated infections
- Terminal complement deficiencies = recurrent systemic infections with Neisseria gonorrhea or meningitides
- autoimmune manifestations like lupus or atypical HUS
- angioedema (specific to C1 esterase inhibitor deficiency)
Diagnosis = CH50 to assess classical complement pathway
- C1 esterase if angioedema
Treatment = vaccination, can replace specific complement (ie. recombinant C1 esterase, FFP), HSCT
