Immunology

Question 0

Allergic rhinitis – clinical features? Diagnosis?

Answer 0

1. Allergic shiners – circles under eyes due to venous congestion
2. Dennie’s lines – creases under eyes to chronic edema
3. Allergic salute – patient uses palm to elevate tip of nose to relieve itching

Skin testing, nasal cytology (>10% eosinophils)

Question 1

Allergic rhinitis – definition? Types? Pathophysiology?

Answer 1

IgE-mediated inflammatory response and nasal mucosa to inhaled antigens

1. Seasonal – pollen
2. Perennial – indoor allergens

Allergen-specific IGE binds to mast cells/basophils, which degranulate

Question 2

Allergic rhinitis – management?

Answer 2

1. Most effective – intranasal steroids
2. Antihistamines (second-generation are safer/better tolerated but no more effective)
3. Cromolyn sodium (Prevents the mast cell degranulation)
4. Decongestants (vasoconstriction to relieve nasal congestion)
5. Leukotriene receptor antagonists

Question 3

Atopic dermatitis – a.k.a.? Acute vs chronic Clinical features? Clinical presentation based on age?

Answer 3

Eczema

1. Acute changes – erythema, crusting, secondary infection
2. Chronic – dry scaly skin, pigment changes, lichenification
3. Infantile – truncal, facial areas (scalp), extensors
4. Early childhood – flexor surfaces, chronic itching, but unification
5. Late childhood - More localized, tendency towards remission

Question 4

Atopic dermatitis – criteria for diagnosis? Management?

Answer 4

3/4:

1. Pruritus
2. Family History of atopy
3. Typical morphology/distribution
4. Relapsing/chronic dermatitis

Avoid triggers, steroids, antihistamines, tepid water baths

Question 5

Laboratory evaluation of allergies?

Answer 5

1. Skin test
2. Radioallergosorbent test (identify serum IGE antibodies to food)
3. Provocative oral food challenge
4. Definitive test – double-blind placebo-controlled challenge

Question 6

Patients at increased risk for latex allergy?

Answer 6

1. Healthcare workers

2. Patients with Myelomeningocele he (repeatedly latex exposure due to urinary catheterizations)

Question 7

Seven disorders of lymphocytes?

Answer 7

1. IGA deficiency
2. Common variable immunodeficiency
3. Severe combined immunodeficiency disease
4. Ataxia telangiectasia
5. DiGeorge syndrome
6. Wisckott-Aldrich syndrome
7. Bruton’s agammaglobulinemia

Question 8

IGA deficiency – clinical features? Diagnosis?

Answer 8

1. Respiratory infections
2. gastrointestinal manifestations
3. Autoimmune diseases (SLE, JRA, celiac)
4. Atopic diseases (allergic rhinitis, eczema, asthma)

IgA <7 mg/dL

Question 9

Common variable immunodeficiency – characterized by? Clinical features? Diagnosis? Management?

Answer 9

Hypogammaglobulinemia

Respiratory infections, gastrointestinal infections, autoimmune disorders

1. Immunoglobulin measurement
2. Diminished antibody function (based on immunization titers)
3. Monthly IV IG replacement
4. Aggressive antibiotic management with infections

Question 10

Ataxia telangiectasia – characterized by? Diagnosis? Management?

Answer 10

1. Combined immunodeficiency (Sinopulmonary infections)
2. Cerebellar ataxia (Wheelchair-bound)
3. Oculocutaneous telangiectasias
4. Also see: café au lait, vitiligo,
5. IgG deficiency
6. Diminished T-cell proliferation

Treat infections, monitor for malignancies, avoid ionizing radiation

Question 11

Wiskott-Aldrich – Triad? Susceptibility to what type of infection? Describe platelets?

Answer 11

1. Combined immunodeficiency
2. Eczema
3. Congenital thrombocytopenia

Encapsulated organisms

Small defective platelets leading to bleeding episodes/intercranial hemorrhage

Question 12

Diagnosis of Wiskott-Aldrich? Management?

Answer 12

1. CBC shows thrombocytopenia and small platelets
2. Decreased IgM
3. Defective antibody response to polysaccharide antigens
4. Do not develop antigen specific cytotoxic T cells

Bone marrow transplant, IVIG, splenectomy

Question 13

Agammaglobulinemia – increased susceptibility to? Diagnosis? Management?

Answer 13

Encapsulated bacteria

1. Decreased in all immuniglobulins
2. B cells are absent
3. T cells present
4. Mutations in BTK gene

Monthly IVIG replacement

Question 14

Chronic granulomatous disease – defect in? Leads to an impairment of the ability to? Clinical features? Pathogens?

Answer 14

Neutrophil oxidative metabolism the NADP H

Inability to kill catalase positive bacteria

Increased susceptibility to infections and abscesses

SPANCKS (staph, Pseudomonas, Aspergillus, nocardia, candida, Klebsiella, Serratia)

Question 15

Chronic granulomatous disease – diagnosis? Management?

Answer 15

Flow cytometric assay >nitroblue tetrazolium

1. Surgically drained abscess
2. Prophylaxis – Bactrim, itraconazole, interferon Gamma
3. Bone marrow transplant

Question 16

Disorders of granulocytes?

Answer 16

1. Chronic granulomatous disease
2. Schwachman-Diamond syndrome
3. Chediak-Higashi

Question 17

Schwachman-Diamond – Characterized by? Patients present with?

Answer 17

1. Decreased neutrophil chemotaxis
2. Cyclic neutropenia
3. Pancreatic exocrine insufficiency

Soft tissue infection, chronic diarrhea, failure to thrive

Question 18

Chediak-Higashi – characterized by? Most common cause of infections?

Answer 18

1. Neutropenia with large granules in neutrophils
2. Thrombocytopenia
3. Oculocutaneous albinism

Staph aureus

Question 19

associated with:

1. Deficiency of early components of classic complement pathway?
2. Deficiency of late components of classic pathway?
3. Deficiency of C1 esterase inhibitor causes?

Answer 19

1. Autoimmune diseases
2. Disseminated gonococcal infection
3. Hereditary angioedema