Flashcards in Allergy & Immunology Deck (124)
What is an important organism to vaccinate against in children with Nephrotic syndrome?
Strep pneumo (pneumococcal polysaccharide 23-valent vaccine is recommended)
What is the risk associated with the oral polio vaccine?
Vaccine viruses are excreted in the stool of the vaccinated person for up to 6 weeks after a dose.
Maximum viral shedding occurs in the first 1–2 weeks after vaccination, particularly after the first dose.
Vaccine viruses may spread from the recipient to contacts. Persons coming in contact with fecal material of a vaccinated person may be exposed and infected with vaccine virus.
What are the CPS recommendations for post-splenectomy antibiotic prophylaxis?
Antibiotic prophylaxis for a minimum of two years postsplenectomy and for all children <5 years of age. Lifelong prophylaxis in all cases is ideal!
What is the percent cross-reactivity between penicillins and cephalosporins?
2% (risk of allergic reaction to cephalosporins in patients with positive skin test responses to penicillin)
What are key features of Wiskott-Aldrich syndrome?
Eczema, thrombocytopenia, recurrent infections, low IgM, high IgE and IgA
Diagnostic criteria for anaphylaxis
Any one of the following three criteria:
- Acute onset of an illness with involvement of the skin and/or mucosal tissue AND at least one of respiratory compromise or hypotension
- Two or more systems involved (skin/mucosa, resp, CV, GI) after exposure to likely allergen
- Reduced BP following exposure to known allergen (>30% drop)
Child with abscesses, lymphadenopathy, serratia infection
Chronic granulomatous disease
Unilateral facial weakness, vesicles in ear canal
Ramsay-Hunt Syndrome (herpes zoster oticus) - treated with acyclovir and steroids
Treatment of type III hypersensitivity reaction (ie serum sickness)
anti-histamine and NSAIDs
How do you diagnose CGD?
nitroblue tetrazolium test for neutrophil oxidative ability
Influenza vaccine and egg allergy - contraindicated?
Administration of inactivated trivalent or quadrivalent influenza vaccines is safe for individuals with egg allergy. Unless children have experienced an anaphylactic reaction to a previous dose of influenza vaccine, they can and should be immunized with a full dose of trivalent or quadrivalent inactivated vaccine. Don’t give the live attenuated vaccine (not tested).
Low IgA, normal IgM and IgG
Can’t be diagnosed until 4 years of age (when IgA reaches adult levels). Occurs in 1/500, most asymptomatic. Associated with recurrent sinopulmonary infections, IgG2 subclass deficiency, food allergy, autoimmune disease and celiac.
What is important to test in a patient with neisseria meningitis?
Terminal complement (C5-9) - the membrane attack complex
What patients respond to allergen immunotherapy?
seasonal/perennial allergic rhinoconjunctivitis, asthma triggered by allergen exposures, and insect venom sensitivity
(no evidence for food allergy, atopic dermatitis, latex allergy, and acute/chronic urticaria)
What can result in false positive RAST testing?
Infections, absent thymus?
Hypocalcemia, congenital heart disease, absent thymus?
SCID genetic defect
x-linked, gamma chain defect of the IL-2 receptor
Hallmark of leukocyte adhesion deficiency
delayed separation of umbilical cord
Classic presentation of SCID
thrush, recurrent sepsis, pneumonia, otitis media, diarrhea, FTT, absent lymphoid tissue
Work up of suspected humoral immunity deficiency
- CBC, diff
- vaccine titres
- RBC isohemagglutinin (IgM)
- CXR (to evaluate for thymus, bronchiectasis)
What is a hallmark sign of CVID?
Recurrent sino-pulmonary infections
IVIG replacement therapy dose
400-600 mg/kg Q3-4 weeks
In what condition could you have anaphylaxis to IVIG?
T-cell problem work-up
- CBC & diff
- intradermal candida skin testing
- T & B cell markers (flow cytometry)
- Day 3 proliferation (mitogen - stimulate proliferation)
- Day 6 proliferation (antigen)
- thymic biopsy
Most common cardiac issue in DiGeorge?
interrupted aortic arch, type B
Can SCID babies be breastfed?
NO. Unless the milk is irradiated.
Features of Omenn's syndrome
Abnormal DNA repair
15% develop malignancy
up to 80% have IgA deficiency