Asthma attack. Asthma attack is an airway disease that involves the air passage thru the airways. Hypersensitivity pneumonitis (hp) involves the actual tissues of the lungs which are beyond the airways. Type of injury is differrent. Asthma attack is an acute reaction. While hp is slower mechanism, and presents with insidious progress. Asthma can also be a slow proccess, when it is poorly controlled.
Immunology. Hypersensitivity pneumonitis is a different type of immunologic reaction in the lung. The list is very long for the causes. In general hp cause a different breathing pattern problem than asthma. While both cause shortness of breath they are treated differently.
Very different. Hp is a hypersensitivity reaction usually to some organic material usually mold, but also food particles, bird droppings, pets, grains, etc. Asthma presents with mostly reversible airway obstruction due to exercise, allergens, infections. Both can present with sob, cough, wheezing, but hp can also have fever. Hp usually resolves or kept from turning into fibrosis, once removed from trigger.
Exposure. Asthma is a disease of chronic inflammation in the airways. Usually it's genetic. It can cause wheezing, shortness of breath, and even chest pain. Hp is a type of allergy reaction that happens in the air sacs. Symptoms can be like asthma, but it is usually brought on by exposure to any of a number of organic substances - from fungus to feathers. Chest xrays and scans are usually abnormal too.
Similar. Asthma is, in most cases, an allergic reaction caused by ige or the allergy antibody. Hypersensitivity pnemonitis is a different immune reaction caused by igg, usually. Both can make one short of breath but the reason for this symptom is different pathology.
What is effected. Asthma is a disease of chronic mid to small airway inflammation, sometimes caused by allergens but not always. Hypersensitivity pneumonitis is inflammation of the lung tissue itself as the result of exposure to allergens (eg birds), it usually resolves when the allergen is removed, although long term exposure can lead to scarring.