A much less common type of asthma, but still just as frightening and uncomfortable, nonallergic asthma is often triggered by temperature extremes and illness, exercise, irritants in the air, stress, and certain medications.
Nonallergic asthma, sometimes called intrinsic asthma, often occurs later in life and is more common in females and may be more severe. The cause of nonallergic asthma is not understood, but researchers believe that a combination of environmental and genetic factors likely play a role in the development.
The treatment of nonallergic asthma is the same as any other type of asthma, with the use of long-acting and short-acting inhalers, as well as avoidance of triggers.
Asthma-COPD overlap syndrome, or ACOS, occurs when asthma and chronic obstructive pulmonary disorder (COPD) coincide.
COPD is a collection of diseases – refractory asthma, emphysema, and chronic bronchitis. It obstructs airflow and breathing difficulties. Not everyone with COPD has asthma before the development of COPD, and not everyone with asthma goes on to the development of COPD. However, those who have both at the same time are said to have ACOS.
Unfortunately for people with ACOS, they may not be diagnosed with the COPD portion until later in the disease state. This happens because symptoms of COPD often mimic symptoms of asthma.
Because ACOS is a combination of both asthma and COPD, if not treated appropriately, ACOS can be deadly. According to the American College of Allergy, Asthma and Immunology, "In 2014, chronic lower respiratory diseases – primarily COPD – were the third leading cause of death in the U.S."
Eosinophilic asthma is a rare form of asthma, affecting only five percent of people living with asthma. According to Medical News Today, this type of asthma is defined as "…a form of asthma associated with high levels of a white blood cell called eosinophils."
So, what does this mean?
Well, the symptoms are strikingly similar; inflamed airways occur, as do shortness of breath and an increased in mucus production. However, a dramatic increase in the eosinophil count occurs, which causes further inflammation of the airways, sinuses, nasal passages, and maybe even the lower airways.
As the eosinophilic count rises, the symptoms worsen. This specific type of asthma can be challenging to treat and can affect the quality of life.
Other conditions that cause increases in the eosinophil count may be attributed to asthma, but eosinophilic asthma often occurs without allergies. As of now, researchers have not pinpointed what causes the body to produce increased levels of eosinophils in people who have this type of asthma.
Eosinophilic asthma treatment may include the use of biologic therapies and leukotriene antagonists.
Occupational asthma is asthma that occurs as a result of exposure to hazards on the job, such as chemical fumes, gases, and dust. Those who have allergies or a family history of asthma are more likely to develop occupational asthma, even if they do not have a prior history of asthma.
Over 250 workplace substances have been identified as possible causes of occupational asthma; here are some of the more common causes:
- Respiratory irritants: smoke, sulfur dioxide, chlorine gas
- Animal substances: dander, hair, scales, fur, saliva, body wastes
- Plant substances: natural rubber latex, cereal, flour, papain, wheat, cotton, hemp, flax, rye
- Chemicals: paint, laminates, soldering resins, varnishes, adhesives, insulation, packaging materials, foam mattresses, upholstery
- Enzymes: detergents and flour conditioners
- Metals: platinum, nickel sulfate, chromium
Avoidance of an occupational irritant is important. Sometimes this is impossible, but care should be taken to minimize exposure if at all possible.
This type of asthma is tricky to diagnose because often the only symptom is a cough, hence the name. The symptoms that we associate with asthma – shortness of breath, difficulty breathing – are not present.
If your physician tells you that you have a chronic cough – a cough that lasts more than six weeks – ask your doctor about the likelihood of cough-variant asthma. Coughing may worsen with exercise, as well as when exposed to other triggers, such as allergens or cold air.
Cough-variant asthma can occur in any age group, but is most common in children. It can progress to "classic" allergy symptoms that we're most familiar with. We aren't sure what causes this type of asthma, but often it is noticed after an illness because the cough never goes away, or after prescribing medication, such as a beta-blocker.
In addition to the various types of asthma, asthma can also be classified based on the severity of symptoms. It is classified into four categories based on subjective and objective measures, peak flow measurements, and spirometry results.
Mild intermittent asthma. Symptoms occur less than twice per week, and nighttime symptoms occur less than twice per month. No medications are needed for long-term control of asthma. Lung function is 80% or more above predicted values.
Mild persistent asthma. Lung function is still 80% or more above predicted values, but symptoms occur three to six times per week, with nighttime symptoms occurring three to four times per month.
Moderate persistent asthma. Symptoms occur daily, with nighttime symptoms occurring over five times per month. These symptoms affect activity and may last for days. Lung function is reduced – less than 80% but greater than 60%.
Severe persistent asthma. Symptoms are continuous, and nighttime symptoms are frequent. Activities are very limited. Lung function is less than 60%.