Allergy & Immunology Flashcards
What is the most important component with atopic conditions?
Parental history of atopy
If one parent has atopic disease, what is the risk for a kid with atopic disease?
50%
If both parents have atopic disease, what is the risk for a kid with atopic disease?
70%
What are some other contributing factors to atopic conditions besides genetics?
Environmental influences/exposures (indoor pets, cigarette smoke, respiratory infections like RSV, and diet)…these can increase or decrease risk
If you get a question about maternal diet with respect to the development of atopy what is the answer?
Mom should have a regular healthy diet without any specific dietary limitations…maternal diet doesn’t play as important a role in subsequent de elopement of atopy as previously believed
Does delaying the introduction of solid foods past 4-6 months prevent the development of atopic disease?
No… Holding off on fish, eggs, or peanut butter won’t prevent allergies to these food items (current research is exploring opposite possibility)
True or False: The mortality of asthma is on the increase?
True
Asthma is more common in which gender and ethnic groups?
Boys, African American, and Hispanic children
What medication delivery is just as effective as nebulizers, even in infants?
HFAs used with spacers
What is indicates for the initial diagnosis of asthma and for ongoing management?
Routine pulmonary function testing
What can be described as a chronic nighttime cough which isn’t alleviated by OTC medications?
Asthma
A nighttime cough can be associated with what 2 things besides asthma?
Sinusitis and GERD (if these are the diagnoses they are looking for, the will be obligated to provide you with additional signs and symptoms
What does spirometry measure?
Inspiratory and expiratory flow rate
Spirometry requires expiration for more than how many seconds?
6
Does spirometry measure total lung capacity or residual volume?
No (spirometry doesn’t provide TLC or a ride home with an RV)
4 things to diagnose intermittent asthma?
- Symptoms 2 or less days a week
- Zero night time awakenings per month
- No interference with normal activity
- Requires short acting beta agonists 2 or less days a week
Treatment for intermittent asthma?
Short acting bronchodilator only as needed
What other 2 names is asthma known as?
Reactive airways disease or hyperresponsive airway disease
What is the atopic march?
Specific order in which atopic conditions present…
- Atopic dermatitis in infants
- Allergic rhinitis in children
- Asthma in children and adolescents
Classification for mild persistent asthma?
- Symptoms more than 2 days a week but not daily
- Night time symptoms or awakenings 1-2 times a month
- Minor limitation with normal activity
- Needs short acting beta agonists more than 2 days a week, but not daily
What is first and second line treatment for mild persistent asthma?
First line is a low dose inhaled steroid. Second line is a leukotriene inhibitor.
Plus a short acting bronchodilator PRN
Classification for moderate persistent asthma?
- Symptoms every day
- Night time awakenings 3-4 times a month
- Need short acting bronchodilators daily
- Some limitation of activity
Treatment for moderate persistent asthma?
Low-medium dose inhaled steroids and long-acting bronchodilator or montelukast
Classification for severe persistent asthma?
- Symptoms throughout the day
- Night time awakenings more than once a week
- Using short-acting bronchodilator several times per day
- Extremely limited activity
Treatment for severe persistent asthma?
High dose inhaled steroids and long acting bronchodilators or montelukast
Which is implicated more commonly as triggers in kids with asthma…bacterial or viral?
Viral infections..even though physicians tend to prescribe antibiotics for kids with a history of asthma and develop fever and cough
What is a typical chest XR finding for asthma?
Peribronchial cuffing (don’t confuse this or atelectasis as a sign of pneumonia)
Name side effects of beta adrenergic agonists.
Tremors, tachycardia, hypokalemia, hyperglycemia, hypomagnesemia
When would you use levalbuterol over albuterol?
Only indicated in patients who have demonstrated excessive tachycardia, tremor, and/or irritability with albuterol (levalbuterol has no hard data to support its therapeutic superiority over albuterol)
When would you use inhaled mucolytics or chest physical therapy for an asthma exacerbation?
Never…there is no role for this
Which patients can experience severe asthma exacerbations?
Any…regardless of the baseline asthma severity
If you are presented with a patient who is having an acute exacerbation of asthma which is not responding to beta adrenergic agonists, what is the next step?
Systemic steroids
Which phase of asthma do steroids affect?
Steroids only inhibit the late phase reaction of asthma (not the early phase)
Which phase of asthma do leukotriene inhibitors affect?
Early phase reaction
Why is an inhaled corticosteroid the best method to control persistent asthma?
Decreases bronchial inflammation and also reduces bronchial hyperresponsiveness
How ca you lessen the risk of oral candidiasis with inhaled corticosteroids?
Mouth rinsing after inhaling a dose
A low pCO2 in the setting of acute asthma reflects what?
Tachypnea
An increasing pCO2 in acute asthma reflects what?
CO2 retention and fatigue
What are signs of hypercapnia (with fatigue in severe asthma)?
Agitation, flushing, mental status change (disorientation), headache, or tachycardia
Why might a kid with an acute asthma exacerbation not be wheezing?
In an acute exacerbation, the child may not be moving enough air to elicit a wheeze…in this case, giving an albuterol nebulizer will actually make the wheezing worse, but it is a good sign
What are triggers noted in the history to tip you off to a correct diagnosis of asthma?
Weather changes, aspirin, beta blockers, viral URI, exercise, allergies
What % of asthmatic children have positive immediate-type allergy skin tests?
80%…so any description of allergic signs and symptoms should make you think of asthma
What is the definition of exercise induced asthma?
Coughing and wheezing 5 minutes after exercising, with gradual improvement with 15 minutes of rest
What type of air is best and worst for exercise induced asthma?
Worst: Cold, dry air
Best: Warm, moist air
Should kids with asthma still exercise?
Yes, it is important to keep in mind that kids with asthma should be encouraged to remain active…EIA exacerbations may be a result of poor asthma control
What is the treatment for EIA when the asthma problems only occur with exercise?
Use of a short acting beta agonist (SABA) 30 minutes before exercise
What signs/symptoms suggest foreign body as the cause of wheezing?
Respiratory infection that isn’t clearing, wheeze that is localized and fixed, reduced breath sounds over one lung, a mediastinal shift seen on CXR, or a very sudden onset
If a foreign body in the lung isn’t removed what can result?
Recurrent pneumonia, atelectasis, or bronchiectasis
What are things to consider for a kid experiencing exercise intolerance besides exercise induced asthma?
Cardiac disease, anemia, muscle weakness, poor conditioning, depression, distraction
What are 4 important risk factors for hospitalization for asthma?
- Chronic steroid use
- Hospitalization within the past year
- Low socioeconomic status, low educational level
- Previous life threatening episode
What are risk factors for asthma persisting into adulthood?
Rule of E's and 3's 3 years of age (onset before 3) IgE Elevation Maternal history of asthma (think of M as sideways E) Eosinophilia
What % of kids with mild asthma will outgrow the symptoms by adulthood?
60%
What % of infants with severe RSV bronchiolitis will develop recurrent wheezing?
50%
A type 1 allergic reaction is mediated by what?
IgE mediated…anaphylactic reaction
Anaphylactic = A = Type 1
A type 2 allergic reaction is mediated by what?
Mediated by antibodies
Body = B = Type 2
What causes a type 3 allergic reaction?
Immune complex/
1 + 2 = 3/Complex
What is a Type IV allergic reaction?
Delayed Hypersensitivity
Poison IV = Roman numeral 4 = IV
When is allergy testing indicated?
Any time symptoms are significant and/or require specific treatment, like in case of…severe atopic dermatitis, allergic rhinitis unresponsive to routine treatment, food allergy, persistent asthma, insect sting allergy, vaccine or drug allergy, latex allergy
What can interfere with the results of skin allergy testing?
Antihistamines…can be tricky with things like antidepressants or other medications that have antihistaminic effects
What is the only antibiotic reaction that can be “skin IgE tested”?
Penicillin allergy
*The IgE mediated reaction is one that begins within 24 hours of exposure…if the reaction occurs later, then it isn’t IgE mediated and not verifiable by skin testing.
What are the chances of a kid who had a previous skin reaction to penicillin having a similar reaction to a cephalosporin?
Less than 10%
What presents with symptoms of runny nose, sneezing, and itchy, swollen, or watery eyes?
Allergic rhinitis
What is present in nasal secretions in patients with allergic rhinitis?
Eosinophils
How does non-allergic rhinitis with eosinophilia syndrome (NARES) present?
Allergy symptoms and eosinophils on nasal smear, but skin tests are negative and serum IgE levels would not be elevated
What is perennial allergic rhinitis due to?
Exposure to indoor allergens such as dust mites and animal dander
What is the first step in treating allergic rhinitis?
Identify and eliminate the offending allergen (followed by medication if necessary)
What is the first line drug treatment for allergic rhinitis?
Nasal steroids
What can be used when indicated for allergic rhinitis (after nasal steroids are used)?
Oral antihistamines or antihistamine-containing eye drops
Does in vitro allergy testing (RAST testing) correlate well with skin prick testing?
Yes
What are 3 reasons in vitro allergy testing (RAST testing) is helpful?
- Children on chronic antihistamines because there is no need to stop these medications
- Preferred in kids with extensive eczema or skin infections limiting testing area
- Testing kids who have had life-threatening allergic reactions to the suspected trigger
What are 2 limitations of IgE testing?
Higher cost and higher false positive rate
When do you need to get rid of a pet for allergy issues?
When it is the clear cause of an exacerbation of symptoms, taking steps to reduce the exposure is usually the answer (because of the emotional attachment kids have to their pets). At the very least, the pet should be kept out of the child’s bedroom at all times.
How does infectious rhinitis present?
In younger children with nasal congestion that is worse in winter
What presents with congestion, rhinorrhea, and post-nasal drainage that is unrelated to any specific triggering or infectious agent?
Vasomotor rhinitis
What can trigger vasomotor rhinitis?
Emotions, pollution, cold drafts, rapid temperature changes, or changes in humidity
What is rhinitis medicamentosa?
Rebound reaction to adrenergic nose drops (results in severe nasal congestion)
What age do you usually not see seasonal allergic rhinitis before and why?
3…Seasonal (outdoor) allergic rhinitis requires repeated exposure over years, and is usually not seen before 3 (beware of history if they are saying things like “hay fever” or making you think the kid is allergic to pollen)
What is the most likely diagnosis in a kid younger than 3 who presents with recurrent rhinorrhea?
Recurrent upper respiratory tract infection
What are kids with allergic rhinitis at risk for?
Sinusitis (this is often underdiagnosed)
In kid with chronic allergic rhinitis, what should you watch for signs of?
Sinusitis
What other upper respiratory issue are kids with chronic allergic rhinitis at increased risk for?
Otitis media
What is oral allergy syndrome?
Caused when certain allergens come in contact with the oral mucosa
Kid with allergic rhinitis who complains of a tingling sensation in or around the mouth when eating a specific food (like raw fruits or veggies)…
Oral allergy syndrome
When are food allergies most common?
In early childhood (and diminish with age)
The prevalence of food allergy is much higher in which kids?
Children with atopic diseases like allergic rhinitis, eczema, and asthma
Which kids should be sent for food allergy testing?
Infants with severe eczema and kids with persistent asthma
What are the most common food allergens in the pediatric population?
Cow milk, eggs, peanuts, tree nuts, soybeans, wheat, fish
Which fruits should someone with a latex allergy avoid?
Avocado, banana, chestnut, fig, kiwi, peach, and tomato
The typical reaction to the consumption of these would be oral allergy syndrome
Milk, egg, and soy allergies are often outgrown by what age?
5
When a 5 year old makes MES it can be cleaned up: Milk, Eggs, Soy
Which allergies to foods are typically not outgrown?
Peanuts, tree nuts, and seafood
What type of reactions are usually rapid in onset and occur within minutes of ingestion and up to 2 hours afterward?
IgE mediated
When does food poisoning usually present?
6 or more hours after ingestion
What two tests have low positive predictive value for food allergy?
Positive skin prick and IgE testing (up to 60% of positive tests don’t reflect actual symptoms on ingestion)
Do negative skin prick and IgE testing rule out food allergy
Yes (virtually)
Allergy test are good screeNs, which are seNsitive to rule out conditions, but no sPecific to diagnose them
What is the only proven therapy after food allergy has been identified?
Strict elimination of the specific food
What should you give to kids with anaphylactic reactions due to food allergies?
Autoinjectable epinephrine
Toddler with moderate to severe atopic dermatitis.. which foods could be triggering it?
Do food allergy testing in order to specify any food allergies triggering the atopic dermatitis
Allergy shots is incorrect and don’t randomly eliminate multiple foods without evidence of correlation. Don’t be tempted to choose eliminating milk, eggs, soy, wheat, and peanuts just because they represent 90% of the foods that can cause atopic dermatitis.
What is a typical anaphylactic reaction categorized as?
Respiratory distress, urticaria, and general discomfort
With what issue do kids usually describe a sense of doom?
Anaphylaxis
What are some signs besides respiratory distress, urticaria, and general discomfort of anaphylaxis?
Angioedema of the lips and eyelids, wheezing, respiratory distress, cough
What are the primary causes of anaphylaxis in kids?
Foods, insect stings, vaccines, and medications
Foods, insect stings, vaccines, and medications are also important causes of what?
Urticaria and angioedema
All patients in anaphylactic shock are considered what?
Unstable
What is the first concern in anaphylaxis?
Airway
What is the second thing done after airway management in anaphylaxis?
Give 0.01 mg/kg of epinephrine 1:1000
This is the strong stuff…not just 1:10,000
What is secondary after airway and epinephrine in anaphylaxis?
Fluids
The sooner the epinephrine is given, the lower the what?
Mortality
Up until what time can all of the symptoms develop with anaphylaxis?
2 hours after ingestion
For anaphylaxis, if you only have readily injectable epinephrine, what is the dosing?
- 30 mg for patients weighing 30 kg or more
- 15 mg for patient weighing less than 30 mg
* Remember, a kid weighing 30kg or greater gets a 0.30mg dose
When would you give a second dose of injectable epinephrine?
May be necessary 10-20 minutes after the first injection if symptoms return
How many epinephrine injectors should patients have?
2… need one for initial dose, then a second for if symptoms return
Do you ever choose antihistamines for an anaphylactic reaction?
No… they may diminish symptoms when given to a kid in anaphylaxis and just serve to give a false sense of security
Eonsinophili is associated with what 2 types of conditions?
Allergic disorders and parasitic diseases
Picture an E becoming a worm
When is urticaria considered chronic?
If it lasts longer than 6 weeks (under 6 weeks is considered acute)
What is the most likely cause of chronic urticaria?
Food
What is the most appropriate long term treatment for chronic urticaria?
2nd or 3rd generation antihistamines like Allegra (fexofenadine), Claritin (loratadine), and Zyrtec (cetirizine)
When do you use first generation antihistamines like diphenhydramine and hydroxyzine in chronic urticaria?
For breakthrough exacerbations
Which class of drug is rarely necessary in the treatment of chronic urticaria?
Steroids
When is allergy testing done for chronic urticaria?
Never…it has no role in identifying a trigger for chronic urticaria
Does a positive skin test for an allergen in a patient with chronic urticaria mean that the allergen is the cause of the chronic urticaria?
Not necessarily…skin tests are good screeNs, with low positive predictive value
What causes contrast reactions?
An osmolality-hypertonicity reaction that triggers the degranulation of mast cells and basophils with release of mediators which then cause the reactions
Are contrast reactions IgE mediated
No
5 year old who experienced a severe allergic reaction to shrimp in past needs CT scan with IV and PO contrast… what precautions should you take?
Reassurance… the risk of a reaction is negligible…the association of shellfish allergy to radiocontrast material (presumably because of the iodine content) is a myth
Don’t be tempted to pre-treat with antihistamines and prednisone
When is the only time pretreatment with prednisone and diphenhydramine indicated?
With a documented history of an adverse reaction to radiocontrast media
How do you distinguish between local reaction from a wasp or bee sting and cellulitis?
With a local reaction from a wasp or bee sting and the local erythema spreading dramatically the following morning, it would just be a local reaction if the kid is afebrile and swelling is non-tender. With fever or tenderness, think cellulitis.
If a kid experiences a localized nonsystemic reaction (even hives), are they at increased risk for future systemic reactions and do they require allergy testing or desensitization?
No increased risk, no allergy testing or desensitization
What is the triad of systemic reactions from hymenoptera stings?
Hypotension, wheezing, and larygneal edema
What needs to be done for any child with a systemic reaction to a bee sting?
Referral to an allergist and prescribed injectable epinephrine to carry at all times
What should be done for any child with a life threatening reaction to a bee sting?
They need venom immunotherapy (allergy shots)
These are 98% effective in preventing future reactions
What is the false negative rate for skin testing and in vitro testing for insect sting allergy and what does this mean?
25%…renders false test results marginally reliable
So if in vitro testing is negative, skin testing is done and vice versa
When can skin testing or in vitro testing be done for insect sting allergy?
Testing must be done 4-6 weeks after the reaction to be reliable
Who is allergy testing with insect bites limited to?
Those experiencing reactions beyond simple local inflammation
When allergy testing is done for insects, do you test for specific ones?
No, testing should be general, not for a specific insect
How many infections can the typical child have and “reassurance” still be the correct answer for worried parents?
One infection a month… especially the case if all they have are self-limited GI and respiratory ailments
What are 2 clues that a question is presenting a child with a potential immunodeficiency?
- Infants and kids not growing or gaining weight as expected
- Suffer from recurrent severe or atypical infections
How do defects in T-lymphocyte function present?
With infections due to opportunistic organisms like Candida, CMV, and Pneumocystis jiroveci
What lab value correlates with T cell dysfunction and why?
Low lymphocyte count… since the majority of circulating lymphocytes are T-cells
Ataxia with discoloration of the conjunctivae, as well as frequent sinus infections and developmental regression?
Ataxia Telangiectasia (AT)
What is the inheritance of ataxia telangiectasia?
Autosomal recessive
What chromosome is the problem with DiGeorge Syndrome?
22… DiGeorge anomaly is part of the group of disorders caused by deletions on the long arm of chromosome 22
What is the mnemonic for DiGeorge Syndrome?
CATCH-22 Cardiac Defects Abnormal Facies Thymic Hypoplasia Cleft Palate Hypocalcemia
Which part of the immune system responds without requiring previous exposure to the trigger?
Innate system
Which part of the immune system responds to a previous exposure to produce antigen-specific antibodies?
Adaptive system
What 2 things is the adaptive immune system composed of?
Cellular and humoral immune systems
Neonatal tetany, congenital heart disease, abnormal T cell function, dysmorphic facies (low set ears), loud murmur, tetany (secondary to hypocalcemia), no parathyroid, small or absent thymus, diarrhea, infections
DiGeorge Syndrome
Why do kids with DiGeorge syndrome have no parathyroid and a small or absent thymus?
Poor development of the pharyngeal pouches
What can be the major presenting problem for kids with DiGeorge?
Infection
What other condition can kids with DiGeorge syndrome present like?
SCID…depends on the degree of thymic hypoplasia
In DiGeorge syndrome what 2 things can parathyroid deficiency cause?
Diarrhea and hypocalcemia (which leads to the tetany)
What is the treatment for DiGeorge Syndrome?
Aimed at the underlying problems (hypocalemia, infection, cardiac defects)
What is the prognosis for DiGeorge Syndrome?
Poor..children may die from sepsis
What is the best therapeutic approach for complete DiGeorge Syndrome?
Thymic transplantation
What TV character can help remember DiGeorge Syndrome?
George from Seinfeld… even when he “murmured” he was loud. He also had dysmorphic features and was always frozen with fear (tetany).
What is caused by a complete absence of lymphocyte (both B and T cell) function?
SCID
How do infants with SCID present?
Usually in the first 3 months of life with a history of failure to thrive, chronic diarrhea, and recurrent opportunistic infections including thrush (other than these findings, the physical exam may be normal)
What lab value is usually off with SCID and is the best screening test?
CBC…most kids have a low white count (but a normal lymphocyte count doesn’t rule out SCID)
Which condition has a complete absence of T cell function no matter what the white count is?
SCID
What is the initial treatment of SCID?
Supportive… care is aimed at the underlying infections
What is essential and curative for SCID?
Bone marrow transplant
If a child with SCID is left untreated, what is the prognosis?
They will die within 2 years of birth
What does ADA (adenosine deaminase) deficiency result in?
Dysfunctional B and T cells (a form of SCID)
What are 3 things that can result in SCID?
- ADA deficiency
- Abnormality of HLA antigen expression
- Abnormal assembly of the cytokine receptors
How is Wiskott-Aldrich Syndrome inherited?
X-linked
Triad of eczema, thrombocytopenia, and cellular immunodeficiency
Wiskott-Aldrich Syndrome
What is the typical presentation of Wiskott-Aldrich Syndrome?
Male infant with eczema, recurrent sinopulmonary infections, and unusual bleeding (bloody diarrhea, bruising, and/or bleeding from circumcision)
What is the mnemonic for WAS?
WBC problems
Atopic Problems
Small lacking platelets
What is the difference in workup results from WAS to idiopathic thrombcytopenic purpura?
WAS shows low platelet count with small platelets… idiopathic thrombocytopenic purpura has a low platelet count with large platelets
What are the initial infections in WAS usually?
Sinopulmonary involving encapsulated bacteria
Eventually the infections are opportunistic infections including herpes viruses and P. jirovenci
What is the treatment for WAS?
Management of bleeding and infections
What can be curative for WAS?
Bone marrow or stem cell transplantation
What is the most common cause of death in patients with WAS?
Lymphoma… they have an extremely high rate of this
What type of immunodeficiencies are most common?
Antibody deficiencies
What is the typical presentation of humoral immune abnormalities?
Recurrent sinopulmonary infections with encapsulated bacteria
When do symptoms appear with humoral immune abnormalities?
4-6 months of age due to initial protection by maternal antibodies
What is the most common primary immunodeficiency?
Selective IgA deficiency
What % of selective IgA deficiency is asymptomatic?
Over 80%
What is the most frequent manifestation of IgA deficiency?
Recurrent sinopulmonary infections
When do you give IVIG for selective IgA deficiency?
You don’t…IgA deficiency isn’t an indication for IVIG replacement because commercial replacement immunoglobulins contain very little IgA
What condition primarily affects B cells and often has an elevated T cell count?
Bruton’s X-linked Agammaglobulinemia
How does the absence of B cells affect the serum levels of Ig in XLA?
The serum levels of IgG, IgA, IgM, and IgE are very low
What happens to lympoid tissues like the tonsils, adenoids, Peyer’s patches, peripheral lymph nodes, and spleen in XLA?
They are reduced in size (due to the absence of B cells)
What is the most common presentation of XLA?
Baby boy with recurrent infections with encapsulated pypgenic bacteria (like Strep pneumo and H. Flu)
How is Bruton’s X-linked agammaglobulinemia inherited?
X-linked
Remember: B cells are the problem in Bruton’s and then think of it as BruXon’s to remember it is X-linked
How do you diagnose XLA?
First measure immunoglobulin levels… when they are all found to be low, then confirm by measuring B and T cell subsets
What do you have to give to kids with XLA to protect them from recurrent bacterial infections?
IVIG
What 2 lung issues are kids with XLA at risk for?
Bronchiectasis and chronic pulmonary insufficiency
What is the most common clinically significant antibody deficiency?
Common variable immunodeficiency
*IgA deficiency is actually the most common primary immunodeficiency, but it is usually not clinically significant
What is CVID characterized by?
A defective antibody response
The B-lymphocytes don’t differentiate into plasma cells, so there is a deficiency of the immunoglobulin subtypes
Most patients have a T-cell defect as well
What types of infections do kids with CVID get?
Recurrent infections of the upper and lower respiratory tract and frequent GI symptoms (malabsorption and chronic diarrhea)
Recurrent herpes and zoster infections are common
What diseases are associated with CVID?
Autoimmune diseases like RA, cytopenias, or thyroid abnormalities. Also increased risk of lymphoma (EBV-associated)
What do you give to kids with CVID to protect them from recurrent bacterial infections?
IVIG
What causes X-linked immunodeficiency with hyperimmunoglobulin M?
Disruption of B cell differentiation
What is the classic presentation of X-linked Hyper IgM syndrome?
Male infant 6-12 months of age with frequent otitis and sinopulmonary infections, as well as diarrhea. Also a high incidence of opportunistic infections.
When are most cases of X-linked Hyper IgM Syndrome diagnosed?
Adulthood
What do labs show with X-linked Hyper IgM Syndrome?
Low levels of IgG, IgA, and IgE
High levels of IgM
What is the hallmark of Hyper IgM Syndrome?
Marked lymphoid hypertrophy despite antibody deficiency
How do you treat X-linked Hyper IgM Syndrome?
IVIG
What explains the presence of Pneumocystis carinii in the absence of HIV infection?
Hyper IgM Syndrome
There is a T cell abnormality that prevents conversion of IgM to IgG
How do you remember what is involved in Hyper IgE or Job Syndrome?
3 E’s: Eosinophilia, Eczema (recurrent skin infections), and elevated IgE (recurrent sinopulmonary infections)
What bacteria normally causes infection in Hyper IgE?
Staph aureus
What 2 unusual problems do kids with Hyper IgE get?
Chronic thrush and multiple fractures and other skeletal abnormalities
What is hyper IgE syndrome often mistaken for and how can you distinguish between these?
Atopic dermatitis… but in atopic dermatitis there will be no skeletal abnormalities and no abnormal facies like in Hyper IgE
How do you distinguish between Wiskott-Aldrich and Hyper IgE?
Boys with Wiskott-Aldrich typically have a milder rash than Hyper IgE, and Wiskott-Aldrich has bleeding problems from thrombocytopenia (there is no bleeding issues in Hyper IgE)
How do you treat Hyper IgE Syndrome?
Antibiotics and steroids
What causes transient hypogammaglobulinemia of infancy?
Decreased T-helper function leads to lower than normal amounts of IgG and IgA
*Unlike XLA and CVID, there is no intrinsic B-cell deficiency
When does transient hypogammaglobulinemia of infancy manifest?
By age 6 months…as the infant breaks down more and more of Mom’s immunoglobulins
When do kids usually outgrow transient hypogammaglobulinemia of infancy?
3-6 years of age
What do labs for transient hypogammaglobulinemia of infanct show?
Severely low IgG levels…IgA may also be low, but IgM is usually normal
What is chronic granulomatous disease a disorder of?
Phagocytic function
What are the defective phagocytes in CGD unable to do that leads to life threatening infections?
Defective phagocytes can’t undergo “respiratory burst” needed to kill ingested bacteria and fungi…this leads to life threatening infections with these pathogens
How is CGD inherited?
2/3 X-linked
Remainder is autosomal recessive
When do most kids with CGD present?
Within first 5 years of life
Which organs are most commonly involved in CGD?
Think of ones that are barriers to infection: Skin, GI tract, lungs, liver, lymph nodes, and spleen
Why do patients with CGD often get urinary retention and bowel obstruction?
These patients often have granulomas of the skin, GI tract, and GU tract (granulomas lead to urinary retention and bowel obstruction)
These are in addition to infection
What are the most common infections and bacteria in CGD?
Deep abscesses, pneumonia, lymphadenitis, osteomyelitis, and systemic infections
S. Aureus, B. Cepacia, Serratia species, fungi
What is the diagnostic test for CGD and what does it assay?
Nitroblue tetrazolium (NBT)…assays phagocytic oxidase activity
What 2 drugs are used for prophylaxis in CGD?
Trimethoprim/sulfamethoxazole and itraconazole
What condition is caused by a defect in chemotaxis (essentially a problem with the white blood cells getting where they have to go and staying there)
Leukocyte adhesion deficiency
What is seen on a CBC in LAD?
High white blood cell count (20,000)…maybe
What types of infections are seen in LAD?
Perirectal abscess, indolent skin infections, omphalitis
What are the findings in infected areas in patients with LAD?
The infected areas have no pus and minimal inflammation (poor chemotaxis)
Wound healing is delayed
What typically results in recurrent infections in the skin, mucosa, and respiratory tract?
LAD (leukocyte adhesion deficiency)
What can have a history of delayed umbilical separation?
LAD
What 2 things can be curative for LAD?
Bone marrow or stem-cell transplantation
In what condition do the WBCs contain lysosomal granules and have abnormal chemotaxis?
Chediak-Higashi Syndrome
What are features of Chediak-Higashi Syndrome?
Frequent infections, easy bruisability, and oculocutaneous albinism
Where do infections in Chediak-Higshi syndrome occur and what are the usual pathogens?
Mostly in lungs and skin
Staph aureus, strep pyogenes, and pneumococcus
What is the inheritance of Chediak-Higashi syndrome?
Autosomal recessive
What is the memory aid for Chediak-Higashi Syndrome?
Cadillac Hibachi: If you sat on a hibachi grill instead of a Cadillac and tried to drive, you wouldn’t go far (poor chemotaxis) and your butt would have some serious granules (lysosomal granules). A Cadillac is a receding “auto”, which should help you remember that CHS is autosomal recessive. The hibachi would burn your skin and the smoke would make you cough (infections of the skin and respiratory tract.
Very fair skinned, blonde, blue-eyed kid with frequent bad skin infections
Chediak-Higashi
How is diagnosis made for Chediak-Higashi syndrome?
Blood smear with giant granules in the neutrophils
What is needed to treat Chediak Higashi syndrome?
Bone marrow transplant (without this most kids die before age 10)
Deficiencies affecting C1-C4 present with what (and due to what bacteria)?
Recurrent sinopulmonary infections
Due to encapsulated bacteria
What deficiency is associated with recurrent Neisseria infections and increased risk of meningitis?
Deficiencies affecting the terminal components C5-C9 of the complement cascade
How are most complement deficiencies inherited?
Autosomal recessive
How do you screen for complement conditions?
Screened by checking a CH50 assay
What is treatment for complement disorders?
There is no therapy
What does nitroblue tetrazolium test and how are results interpreted?
Tests neutrophil activity (not number)
Normal turns blue, abnormal stays colorless
What disease shows a deficiency in the NBT test?
Chronic granulomatous disease
What tests the complement system?
CH50
What do you order if they describe repeated serious bacterial infections?
CH50
To test for issues with the complement system
What tests for cell-mediated immunity associated with T-cell defects such as AIDS?
TB/Candida skin test
When do you check immunoglobulin levels?
To test the humoral system
How do humoral system defects manifest?
Recurrent less serious infections
When do humoral system defects manifest?
After 6 months of age…rarely seen before 6 months of age because of presence of Mom’s antibodies
*Look for the words…“healthy until 6 months”
When would you do specific antibody tests?
If IgG levels are normal and a humoral defect is still suspected…can check for subclasses from vaccination (tetanus, rubella, pneumococcus, ect)
When would you do a CBC in the setting of immunodeficiency?
To check lymphocyte count in cellular deficiencies associated with opportunistic infections
