Asthma Vs. Reactive Airway Disease

The terms "reactive airway disease" and "asthma" are often used interchangeably, but this is inaccurate. In reality, they aren't synonymous. Reactive airway disease (RAD) is an informal term that medical professionals use to describe conditions with symptoms similar to the signs of asthma.

Doctors sometimes diagnose RAD when they are unsure if a patient has asthma. This diagnosis demonstrates that more testing is needed to confirm the respiratory condition. This diagnosis helps doctors characterize the patient's symptoms to determine the next best course of action.

What is reactive airway disease?

Reactive airway disease is an informal term that medical professionals use to describe conditions in which bronchial tubes react to an irritant, like allergens, viral infections, or weather, and cause asthma-like symptoms, such as wheezing, coughing, and shortness of breath. In most cases, the physician diagnoses a person with RAD when they suspect asthma but cannot draw a confirmation.

RAD controversy

There is significant controversy over using reactive airway disease as a diagnosis. This term doesn't exist in the "Diseases of the respiratory system" section of the International Classification of Diseases,¹ which healthcare providers use for billing and reimbursements. 

According to medical professionals, RAD doesn't have a clinical meaning. The term is non-specific, so coming up with a specific course of treatment isn't always possible. In most cases, doctors say that their patients have "reactive airways" when they experience such symptoms as:

• Cough

• Wheezing

• Sputum production

• Dyspnea (difficulty breathing)

When a doctor diagnoses a patient with RAD, the physician is not certain about the reason behind respiratory symptoms. This diagnosis calls for further testing and monitoring for specific determination of illness. In some cases, these patients will end up being diagnosed with asthma.

The problem with RAD as a diagnosis is that it may give a physician a false sense of security. It may prevent them from running tests to identify what may have actually caused these respiratory symptoms in the first place.

Patients with RAD symptoms could suffer from COPD (Chronic Obstructive Pulmonary Disease), including emphysema, chronic bronchitis, or pneumonia. Lifelong smokers are 50%² more likely to develop conditions like COPD, which requires significantly different treatment from remedies for other respiratory problems such as asthma. 

RAD versus RADS

Reactive airway disease and RADS (Reactive Airways Dysfunction Syndrome) are two different diseases. The similarity of abbreviations can be confusing to the patient. RADS is a condition characterized by asthma-like symptoms. These symptoms are usually triggered by a single exposure to high doses of certain irritants, such as vapor, fume, or smoke.

While symptoms are highly similar to asthma, patients with RADS may not respond well to common asthma treatments. The majority of people with this condition will make a full recovery if the exposure to the irritants is short-lived. However, if symptoms do not stop within six months, there is a high chance of the condition becoming chronic and significantly hindering the patient’s quality of life. 

Pediatric reactive airway disease

The most common time doctors diagnose reactive airway disease is during pediatric care. In very young children, diagnosing asthma can be problematic since:

• They might not have much personal or medical history

• Lung function tests are hard to perform.

Diagnosing asthma in children under five is controversial because it's hard to pinpoint the criteria. Many children outgrow the condition by school age.

As many as 80%³ of children develop asthma symptoms before their fifth birthday. However, asthma is often incorrectly diagnosed. For this reason, a doctor may decide to use RAD as a diagnosis and choose to observe the child for some time before making conclusions about asthma.

Symptoms of reactive airway disease 

Symptoms of RAD in both adults and children are similar to asthma symptoms. They can include:

• Wheezing

• Coughing

• Tachycardia (fast heart rate)

• Poor feeding in infants

• Dyspnea

• Tightness in the chest.

Overall, the symptoms of RAD indicate irritation of the airways and your body's reaction to it. If you are experiencing these symptoms, you must speak to your doctor. Even if your doctor diagnoses RAD instead of asthma or COPD, they will design a treatment plan to help alleviate the symptoms while you wait for the correct diagnosis.

Causes and risk factors of RAD versus asthma

The underlying cause of RAD is often an initial infection. Symptoms of the condition have triggers; when exposed to specific irritants, the airways overreact and swell. This swelling makes it hard to breathe and initiates asthma-like symptoms.

Common triggers include:

• Allergens, including pet dander, pollen dust mites, tobacco smoke, pests, mold, cleaning agents

• Stress

• Changes in weather

• Exercise

• Perfumes.

RAD may lead to an asthma diagnosis. Asthma often develops at a young age, although adults can also develop asthma through exposure to certain risk factors. The risk factors that could lead to asthma include:

• Family history: people whose parents have asthma are three to six times more likely to develop the condition.

• Viral respiratory infections: respiratory problems at a young age can cause symptoms such as wheezing. In some cases, this can develop into chronic asthma.

• Allergies: allergic conditions like eczema and hay fever are risk factors for developing allergic asthma.

• Irritant exposures: if exposed to specific irritants in an industrial work environment, like chemical fumes or wood dust, asthma may develop.

• Smoking: cigarette smoke, including second-hand smoke or exposure during gestation, increases the risk of developing asthma.

• Air contamination: living in dense cities with high levels of smog can lead to asthma.

• Obesity: the exact link⁴ is unclear, but people carrying excessive weight are at a greater risk of developing asthma than those in a healthy weight range. 

One of the key parts of the asthma management plan is identifying triggers, trying to avoid them, and learning how to respond to them when exposed.

How to diagnose RAD

Since RAD is a preliminary or informal diagnosis, a doctor may use it to demonstrate the need for further testing.

An important part of this testing is checking for underlying conditions that could be causing RAD symptoms. They may include emphysema, bronchitis, or pneumonia. Once the doctor rules these conditions out, they can run common tests for asthma.

Spirometry

Spirometry⁵ (also called the lung function test) is the simplest and most widely-used test for diagnosing asthma. During the test, you breathe into a mouthpiece, which is connected to a computer. The device measures how efficiently air enters and exits the lungs and if there is any airway constriction. 

You may need to repeat the tests several times at certain intervals. The doctor may give you a bronchodilator, a medication to dilate your airways, to see if there are any notable differences. If your test results improve after the bronchodilator, you may have asthma. If not, the doctor may leave RAD as the diagnosis and order different tests.  

Methacholine challenge test

The doctor may perform a methacholine challenge test if it has been a while since you had RAD symptoms. This test can help them understand how well your lungs work by demonstrating the responsiveness of your airways.

During the test, the doctor will give you an inhaler with methacholine. This drug narrows your airways. After inhaling methacholine, you will complete a breathing test to determine the extent of airway constriction in response to this medication.  

If methacholine causes a 20%⁶ or higher decrease in your breathing ability, your airways are considered reactive, and there is a possibility that you have asthma. 

Can reactive airway disease develop into asthma?

Reactive airway disease is often a preliminary asthma diagnosis. If a doctor diagnoses you with RAD, they may suspect you have asthma. In some children, RAD may never develop into asthma. Symptoms often go away before they reach school age.

RAD treatment 

While RAD isn't asthma, the treatment options for these conditions are similar. Before diagnosing asthma, the doctor can provide fast-acting medications to relieve the symptoms. These work by relaxing the walls of your airways. Your reaction to asthma medication can help your doctor make the correct diagnosis.

The lowdown

Reactive airway disease and asthma aren't interchangeable terms. When doctors say that you have RAD, they are usually unsure as to whether you have asthma. Such a diagnosis warrants additional testing and confirmation of asthma or other respiratory or lung-related conditions.

If you are experiencing asthma-like symptoms, it's imperative to contact your doctor immediately. Even if they don't diagnose the condition right away, they can prescribe medication to relieve your symptoms and prevent serious breathing problems.