Allergy & Immunology Flashcards
Clinical Manifestation:
- recurrent or unusual lymphadenitis
- hepatic abscesses
- osteomyelitis at multiple sites
- unusual infections with catalase-positive organisms
Chronic granulomatous disease
In CGD patients, recurrent infection begins early in life. Also, pneumonia and suppurative adenitis are especially common.
List the four catalase-positive organisms that commonly infect children with chronic granulomatous disease.
- S. aureus
- Aspergillus
- Serratia marcescens
- Burkholderia cepacia
Chronologic age vs. gestational age
How should vaccines be administered in preterm infants?
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.
When should HBV be withheld in a neonate for medical reasons?
If the neonate is =2kg (4lb 6oz) the first hepatitis B vaccination should be withheld.
Pathophysiology:
Chronic granulomatous disease
inherited immunodeficiency marked by an inability to oxidize pathogens within phagocytes.
Clinical manifestation:
Leukocyte adhesion defect type 1
- delayed separation of the umbilical cord
- recurrent bacterial infections of the skin and mucosa
- necrotic periodontal infections
Diagnosis:
- Leukocytosis with neutrophil predominance
- Absence of neutrophils in inflamed or infected tissues
Leukocyte adhesion defect type 1
What are the contraindications to rotavirus vaccination?
- Anaphylaxis to vaccine ingredients
- History of intussusception
- History of uncorrected congenital malformation of the gastrointestinal tract (eg, Meckel’s diverticulum)
- Severe combined immunodeficiency disease (SCID)
Intussusception is a possible side effect of the rotavirus vaccination.
What is the relationship between hepatitis B vaccination and hepatocellular carcinoma?
HBV vaccination decreases the incidence of hepatocellular carcinoma, especially in regions with high levels of hepatitis B infection (eg, Asia & Africa).
What are the diagnostic features of SCID?
- Recurrent bacterial, viral and fungal infections
- Absent lymph nodes and tonsils
- Lymphopenia
- Absent thymic shadow of chest x-ray
- Abnormal T, B and NK cell enumeration by flow cytometric analysis
How do primary humoral immune deficiency syndromes commonly present?
Recurrent or severe sinopulmonary infections are characteristic of primary humoral immune deficiency syndromes.
Diagnosis:
- High IgM levels
- Low or absent IgG and IgA
- Normal lymphocyte population
Hyper-IgM syndrome
Pathogenesis:
Hyper-IgM syndrome
Hyper-IgM syndrome is caused by a CD40 ligand defect.
What are the contraindications for future administration of pertussis-containing vaccines?
- Immediate anaphylaxis
- Unstable neurologic disorders
- Encephalopathy within a week of DTaP administration
When do patients with genetic B-cell deficiencies begin to develop recurrent infections?
The clinical manifestations of genetic B-cell deficiencies begins after the patient turns 6 months.
Due to their deficient humoral immune response, which organisms are patients with genetic B-cell deficiencies predisposed to?
- 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.
- Lack of IgA predisposes these patients to Giardia infection.
When should parental wishes regarding withholding therapy in the medical care of a child be honored and documented?
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.
Clinical manifestation:
Bruton’s agammaglobulinemia
- male infant (typically)
2. recurrent pneumonia and otitis media after age 6-9 months
Diagnosis:
Bruton’s agammaglobulinemia
- Decrease in levels of all immunoglobulins
2. Decrease in circulating B-cells
Clinical manifestation:
rapid-onset edema of the face, acral extremities, genitals, trachea and abdominal organs WITHOUT urticaria
Hereditary angioedema
acral extremities=limbs, fingers, toes, ears, etc.
Pathogenesis:
Hereditary angioedema
deficiency or dysfunction in C1 inhibitor –> elevated levels of C2b and bradykinin –> C2b and bradykinin are edema producing factors
