BRS Allergy and Immunology Flashcards
anaphylaxis is an ______ mediated reaction
IgE
antigen binds to IgE on the surface of mast cells and basophils –> release of potent mediators that affect vascular tone and bronchial reactivity
clinical features of anaphylaxis
pruritus, flushing, urticaria, angioedema
dyspnea and wheezing
N/V/D
cardiovascular sxs, mild hypotension to shock
how to tx anaphylaxis
epinephrine!!!
also systemic antihistamines, steroids, beta agonists
allergic rhinitis is an _____ mediated inflammatory response in the nasal mucosa to inhaled antigens
IgE
clinical signs of allergic rhinitis
allergic shiners
dennie’s lines- creases under the eyes 2/2 chronic edema
allergic salute
things associated with allergic rhinitis
otitis media
sinusitis
atopic dermatitis (eczema)
food or drug allergies
how to dx allergic rhinitis (besides H&P)
- total IgE concentration is elevated
- can do allergen skin testing- *D/C antihistamine 4-7 days prior to testing
- nasal smear for cytology- look for > 10% eosinophils
how to tx allergic rhinitis
- avoid allergens
- drugs include
- ->intranasal steroids (most effective)
- ->first and second generation antihistamines
- ->intranasal cromolyn sodium
- ->decongestants for short period of time (insomnia, nervousness, rebound rhinitis)
- immunotherapy
chronic inflammatory dermatitis- dry skin, lichenification (thickening of the skin), pruritus
eczema (atopic dermatitis)
eczema is worse in the _____ (summer/winter)
winter
skin findings of eczema
acute- erythema, weeping, crusting
chronic- lichenification, dry scaly skin, pigmentary changes (typically hyper pigmentation)
infantile form of eczema
truncal and facial areas, scalp, extensor surfaces
early childhood form of eczema
flexural surfaces, lichenification (hallmark of chronic scratching)
how to dx eczema
3/4 major criteria are needed
- pruritus
- personal or FHx of atopy
- typical morphology and distribution
- relapsing or chronic dermatitis
how to tx eczema
avoid triggers
low to medium potency topical steroids
antihistamines to avoid itching at bedtime
baths in lukewarm water, moisturize well
food allergy is an ____ mediated response to food antigens
most common foods:
exclusive breastfeeding for 6 months may ____ (increase/decrease food allergies)
IgE
egg, milk, peanut, soy, wheat, fish
decrease
how to dx food allergy
mostly by history
- can do skin test
- RAST tests identify serum IgE to specific food antigens
- double blind placebo controlled food challenge is the definitive test
insect venom allergy is _____ mediated
how to tx?
IgE
tx with cold compresses, analgesics, antihistamines, systemic steroids, immunotherapy
circumscribed, raised, evanescent (vanishing) areas of edema that are almost always pruritic
urticaria (hives)
chronic urticaria lasts > _______
can be 2/2 malignancy and rheumatologic dzs
many ppl with chronic urticaria have ____ antibody to ____ receptor
6 months
T
IgG antibody to the IgE receptor
drug allergy is mediated by _____ or ______
most common drug allergies:
IgE or direct mast cell degranulation
PCN, sulfonamides, cephalosporins, AS, NSAIDs, narcotics
phagocytic cells NK cells toll-like receptors mannose binding protein alternative pathway of complement *these are all parts of the \_\_\_\_\_ immune system
innate
selective IgA deficiency is serum IgA levels < _____
this is the most common immune deficiency
7 mg/dL
sxs and signs of selective IgA deficiency
respiratory infections
GI infections
autoimmune and rheumatic disease
atopic diseases
how to tx IgA deficiency
just manage the infections and other stuff
you cannot replace IgA
hypogammaglobulinemia
-normal numbers of B and T cells but variable degrees of T cell dysfunction
common variable immunodeficiency
clinical features of common variable immunodeficiency
respiratory infections- Hflu, Moraxella, strep pneumo
GI infections
autoimmune disorders
increased risk of malignancy
how to dx common variable immunodeficiency
- decreased serum immunoglobulin concentrations
- measure titers generated in response to childhood immunizations- this will show diminished antibody function
how to tx common variable immunodeficiency
monthly IVIG
manage infections with abx
manage GI issues with nutritional support
profoundly defective T cell and B cell function
SCID
2 types of SCID
- X linked SCID- 50% of all cases, caused by deficiency of common gamma chain of receptor for cytokines
- autosomal recessive SCID
increased infection within first few months of life with common pathogens and opportunistic infections (candida, PCP)
- chronic diarrhea
- FTT
SCID
how to dx SCID
- persistent lymphopenia (<1500)
- flow cytometry shows decreased # of T cells
- severe hypogammaglobulinemia
- T cell responses to mitogens and antigens are depressed
how to tx SCID
monthly IVIG
PCP ppx with bacterium
bone marrow transplant can be curative
-if getting blood products, they should be irradiated to prevent GVHD
combined immunodeficiency, cerebellar ataxia, oculocutaneous telangiectasias, predisposition to malignancy
what is it, how inherited, what chromosome
ataxia telangiectasia
autosomal recessive
long arm of chromosome 11
how does the immunodeficiency in ataxia telangiectasia usually manifest
chronic sinopulmonary infections
course of ataxia in ataxia telangiectasia
progressive.. many are wheelchair bound by teen years
where do you see telangiectasias in ataxia telangiectasia
first on the bulbar conjunctiva then later on on exposed skin and areas of trauma
how to dx ataxia telangiectasia
- quantitative measurement of serum immunoglobulins- deficient IgE or IgA
- skin test anergy and diminished T cell proliferation to mitogens on evaluation of T cell function
how to tx ataxia telangiectasia
tx neuro complications
abx for infections
monitor for malignancies
avoid ionizing radiation- 2/2 faulty DNA repair mechanisms
what is digeorge syndrome
CATCH-22 cardiac defects abnormal facies thymic hypoplasia cleft palate hypocalcemia 2/2 deletion on chromosome 22q11
X linked disorder
combined immunodeficiency, eczema, congenital thrombocytopenia with small defective plts
wiskott-aldrich syndrome
with wiskott-aldrich syndrome, what infections are you susceptible to?
encapsulated organisms- strep pneumo, h flu
how to dx wiskott-aldrich syndrome
CBC- thrombocytopenia with small defective plts
Ab response to polysaccharide antigens is defective
cellular immune function is defective, anergy is present, antigen- specific cytotoxic T cells don’t develop
how to tx wiskott-aldrich syndrome
- HLA-matched BMT is preferred
- IVIG for hypogammaglobulinemia
- splenectomy cures the low plts but you must give ppx abx or IVIG regularly after splenectomy
severe hypogammaglobulinemia with paucity of mature B cells but normal T cell number and function
what is it, what is it caused by, what does it put you at risk for
Bruton’s (X-linked) agammaglobulinemia
- BTK gene mutation
- high risk for encapsulated bacteria, staph aureus, and chronic enteroviral infection
how to dx bruton’s agammaglobulinemia
low immunoglobulin levels in general
no B cells
T cells are fine
mutations in the BTK gene
how to tx bruton’s agammaglobulinemia
monthly IVIG
defective neutrophil oxidative metabolism 2/2 issues with the NADPH system –> problems with intracellular killing of catalos-positive bacteria and some fungi
chronic granulomatous disease
increased susceptibility to infections, esp to forming abscesses
chronic granulomatous disease
how to dx chronic granulomatous dz
NBT test
flow cytometry
-they both demonstrate defective neutrophil oxidative burst
how to tx chronic granulomatous dz
- drain abscesses
- ppx with bacterium, itraconazole, and interferon-gamma
- BMT is curative
decreased neutrophil chemotaxis, cyclic neutropenia, pancreatic exocrine insufficiency –> recurrent soft tissue infection, chronic diarrhea, FTT
AR disorder
schwachman-diamond syndrome
neutropenia and thrombocytopenia, giant lysosomal granules in neutrophils, issues with neutrophil/monocytes/NK cell function –> staph aureus infection, partial oculocutaneous albinism
chediak-higashi syndrome
most complement deficiencies are inherited in an ____ way
AR
deficiency early components of the classic complement pathway (_____) are associated with ______
C1q, C2, C4
autoimmune diseases
deficiency late components of the classic complement pathway (______) are associated with ________
C5, C6, C8
disseminated meningococcal and gonococcal infections
deficiency of ______ causes angioedema
C1 esterase inhibitor
what does a normal CH50 mean for complement deficiency?
all components of the classic pathway are present and functional
how to manage complement deficiency
- monitor for infections and autoimmune diseases
- fibrinolysis inhibitors and attenuated androgens for angioedema
adenosine deaminase deficiency is a form of _____
SCID
