Lecture 12 Flashcards
1
Q
What is asthma?
A
- Asthma is a chronic inflammatory disease of the airways, characterized by airflow obstruction, and bronchospasm
- It is episodic
2
Q
What are the symptoms of asthma?
A
- wheezing, cough, sputum production, chest tightness, and shortness of breath associated with airway hyperresponsiveness
3
Q
Epidemiology of asthma?
A
- 1 in 6 adults and 1 in 4 kids in nz
- NZ has growing asthma prevalence, NZ one of worst nations
- Developed countries more than undeveloped
- In children males > females, in adults females > males
4
Q
How is asthma diagnosed?
A
- Physical Examination: Wheezing, high‐ pitched whistling sounds, (But, wheezing is not specific for asthma)
- History of any of the following: Cough, Recurrent wheeze, Recurrent dyspnea, Recurrent chest tightness, Reversible airflow limitation and diurnal variation
- Lung function test: evidence of variable airflow obstruction
5
Q
What are some atypical presentations of asthma?
A
- Dyspnea without wheezing
- Chronic cough
- Increased shortness of breath at nighttime
- Allergic rhinitis with wheezing
6
Q
What lab studies can be done to help diagnose asthma?
A
- Lung function tests
- Peak expiratory flow (PEF)
- Spirometry: FEV1 (a better measure for asthma)
- Skin allergy test and serologic studies
- Radiographic studies
7
Q
How will an asthma patient’s spirometry test differ from a normal patients?
A
- For asthma:
- FEV1 ↓↓
- FVC ↓
- FEV1/FVC ↓
8
Q
What blood tests are done to help diagnose asthma?
A
- Eosinophil count: >4 % or 300 ‐ 400/mm3 (> 800 /mm3 suggests the presence of other disorders)
- Increased Serum IgE leve
9
Q
What allergy tests are done?
A
- Tree, grass, weed and flower pollens
- Dust mites
- Mold and mold spores
- Animal Dander
- Insect allergens
- Smoking
10
Q
What are the pathogenisis models for asthma?
A
- allergy pathway model
- non‐ allergy pathway model
11
Q
What is atopic asthma?
A
- The most common type of asthma
- Usually begins in childhood, early-onset
- Trigged by environmental antigens
- A positive family history
- Often preceded by allergic rhinitis, urticaria or eczema.
12
Q
How does the histology of the airway differ in asthma pateints?
A
- Epithelium broken down
- More inflammatory cells:
- Eosinophils
- Mast cells
- Macrophages
- T cells
- Neutrophils
- Basophils
- Dendritic cells
13
Q
What are the 2 responses to allergens in asthma?
A
- The Acute-Phase Response
- In the acute-phase response (APR), inhalation of allergen causes an immediate fall in lung function (as short as 5-10 min).
- Late-phase response (LPR)
- beginning about 4 to 6 hours after allergen challenge.
14
Q
What mechanism –> acute phase response?
A
- Allergens causing mast cells to secrete histamines etc –> SM constriction
15
Q
What mechanism –> late-phase response?
A
- Allergen –> dendritic cells which recruits inflammatory cells
