Allergy & Immunology

Question 1

Clinical Manifestation:

1. recurrent or unusual lymphadenitis
2. hepatic abscesses
3. osteomyelitis at multiple sites
4. unusual infections with catalase-positive organisms

Answer 1

Chronic granulomatous disease

In CGD patients, recurrent infection begins early in life. Also, pneumonia and suppurative adenitis are especially common.

Question 2

List the four catalase-positive organisms that commonly infect children with chronic granulomatous disease.

Answer 2

1. S. aureus
2. Aspergillus
3. Serratia marcescens
4. Burkholderia cepacia

Question 3

Chronologic age vs. gestational age

How should vaccines be administered in preterm infants?

Answer 3

Chronologic age

In example, a preterm infant should receive HBV at birth, and Rotavirus, Hib, TDaP, pneumococcal and inactivated polio vaccination exactly two months after birth.

Question 4

When should HBV be withheld in a neonate for medical reasons?

Answer 4

If the neonate is =2kg (4lb 6oz) the first hepatitis B vaccination should be withheld.

Question 5

Pathophysiology:

Chronic granulomatous disease

Answer 5

inherited immunodeficiency marked by an inability to oxidize pathogens within phagocytes.

Question 6

Clinical manifestation:

Leukocyte adhesion defect type 1

Answer 6

1. delayed separation of the umbilical cord
2. recurrent bacterial infections of the skin and mucosa
3. necrotic periodontal infections

Question 7

Diagnosis:

1. Leukocytosis with neutrophil predominance
2. Absence of neutrophils in inflamed or infected tissues

Answer 7

Leukocyte adhesion defect type 1

Question 8

What are the contraindications to rotavirus vaccination?

Answer 8

1. Anaphylaxis to vaccine ingredients
2. History of intussusception
3. History of uncorrected congenital malformation of the gastrointestinal tract (eg, Meckel’s diverticulum)
4. Severe combined immunodeficiency disease (SCID)

Intussusception is a possible side effect of the rotavirus vaccination.

Question 9

What is the relationship between hepatitis B vaccination and hepatocellular carcinoma?

Answer 9

HBV vaccination decreases the incidence of hepatocellular carcinoma, especially in regions with high levels of hepatitis B infection (eg, Asia & Africa).

Question 10

What are the diagnostic features of SCID?

Answer 10

1. Recurrent bacterial, viral and fungal infections
2. Absent lymph nodes and tonsils
3. Lymphopenia
4. Absent thymic shadow of chest x-ray
5. Abnormal T, B and NK cell enumeration by flow cytometric analysis

Question 11

How do primary humoral immune deficiency syndromes commonly present?

Answer 11

Recurrent or severe sinopulmonary infections are characteristic of primary humoral immune deficiency syndromes.

Question 12

Diagnosis:

1. High IgM levels
2. Low or absent IgG and IgA
3. Normal lymphocyte population

Answer 12

Hyper-IgM syndrome

Question 13

Pathogenesis:

Hyper-IgM syndrome

Answer 13

Hyper-IgM syndrome is caused by a CD40 ligand defect.

Question 14

What are the contraindications for future administration of pertussis-containing vaccines?

Answer 14

1. Immediate anaphylaxis
2. Unstable neurologic disorders
3. Encephalopathy within a week of DTaP administration

Question 15

When do patients with genetic B-cell deficiencies begin to develop recurrent infections?

Answer 15

The clinical manifestations of genetic B-cell deficiencies begins after the patient turns 6 months.

Question 16

Due to their deficient humoral immune response, which organisms are patients with genetic B-cell deficiencies predisposed to?

Answer 16

1. Due to failed humoral response, these patients are unable to destroy encapsulated organisms and commonly develop recurrent sinopulmonary infections with H. influenzae and S. pneumoniae.
2. Lack of IgA predisposes these patients to Giardia infection.

Question 17

When should parental wishes regarding withholding therapy in the medical care of a child be honored and documented?

Answer 17

As long as no significant harm is likely to result, parental request to withhold therapy in the medical care of their child should be honored.

Question 18

Clinical manifestation:

Bruton’s agammaglobulinemia

Answer 18

1. male infant (typically)

2. recurrent pneumonia and otitis media after age 6-9 months

Question 19

Diagnosis:

Bruton’s agammaglobulinemia

Answer 19

1. Decrease in levels of all immunoglobulins

2. Decrease in circulating B-cells

Question 20

Clinical manifestation:

rapid-onset edema of the face, acral extremities, genitals, trachea and abdominal organs WITHOUT urticaria

Answer 20

Hereditary angioedema

acral extremities=limbs, fingers, toes, ears, etc.

Question 21

Pathogenesis:

Hereditary angioedema

Answer 21

deficiency or dysfunction in C1 inhibitor –> elevated levels of C2b and bradykinin –> C2b and bradykinin are edema producing factors