Question

Mary is an eight year old girl in the third grade. She was excited to have a chance to bring home the class pet hamster. Mary caught her first cold of the year that weekend and developed a hacking cough. Two weeks later Mary's teacher said to her mother at a parent teacher meeting that she thought Mary was coughing on purpose for attention in school because it was consistant. Mary's mother took her to their family health care provider for evaluation. Mary had wheezing in her lungs and a persistant dry cough Mary was diagnosised with asthma.

Answer 1

1. Potential triggers for Mary's asthma could be any of the proteins found in the hamster's flakes of skin (dander), saliva, urine or even fine particles from animal fur.

2.Apart from wheezing other symptoms associated with asthma are : breathlessness, tightness in the chest,coughing. During severe asthma attack one can have :faster breathing ,a fast heartbeat, drowsiness, confusion, exhaustion or dizziness, blue lips or fingers and even fainting.

3.Pathophysiology of asthma: Basically asthma has 3 components:

Chronic airway inflammation: usually triggered by an allergen like dust,pollen or animal protein. Sometimes it can have a genetic basis.. It activates immune cells in our lungs which gather around the airways. These immune cells secrete a lot of chemicals which affect the functioning and growth of the cells lining the airway.

Airway hyperreactivity and re-modelling: Growth factors secreted by immune cells activate smooth muscle cells to increase in size as well as to hypersecrete mucus.Excessive mucus leads to coughing.

Airway closure: Smooth muscle hypertrophy and their contraction plus mucus plugs cause reduction in airway diameter leading to increased resistance to airflow. This leads to wheezing and difficulty in breathing.