Reactive airway disease | |
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Specialty | Pulmonology |
Reactive airway disease (RAD) is an informal label that physicians apply to patients with symptoms similar to those of asthma. [1] An exact definition of the condition does not exist. [1] [2] Individuals who are typically labeled as having RAD generally have a history of wheezing, coughing, dyspnea, and production of sputum that may or may not be caused by asthma. Symptoms may also include, but are not limited to, coughing, shortness of breath, excess mucus in the bronchial tube, swollen mucous membrane in the bronchial tube, and/or hypersensitive bronchial tubes.[ medical citation needed ] Physicians most commonly label patients with RAD when they are hesitant about formally diagnosing a patient with asthma, which is most prevalent in the pediatric setting. While some physicians may use RAD and asthma synonymously, there is controversy over this usage.
More generally, there is controversy over the use of RAD as a label in the healthcare setting, largely due to the ambiguous definition that the term has. [1] [3] Since RAD is not recognized as a real clinical diagnosis, its meaning is highly inconsistent and may cause confusion and misdiagnosis within the medical community. [1] There are also concerns with overtreatment and undertreatment with RAD amongst physicians, since there is little formality with the label. [1] Other problems that healthcare workers have with the use of the RAD label include its exclusion in the International Statistical Classification of Diseases and Related Health Problems, which can lead to billing issues in hospitals and other health care facilities, and the creation of a fabricated sense of security when using it has a diagnosis. [1]
RAD can be confused with reactive airways dysfunction syndrome, an asthma-like disorder that results from high exposure to vapors, fumes, and/or smoke. Unlike RAD, reactive airways dysfunction syndrome is recognized by multiple societies as a real clinical syndrome, including the American Thoracic Society and the American College of Chest Physicians. [1]
The term reactive airway disease originally began to appear in medical literature in the 1980s in reference to asthmatic patients with hyperactive airways, which is a common feature of asthma. This feature is characterized by increased bronchoconstriction reactions in response to stimuli that should not elicit so strong of response. These stimuli can include methacholine, histamine, and distilled water. However, while this was how the term initially was introduced, RAD soon began to be used interchangeably with the term asthma itself, which has led to the current controversy over its place in medical diagnoses. [3]
More commonly, RAD is now mostly used by physicians when they are hesitant to diagnose a patient with asthma. This is most prominent in pediatric settings for a variety of reasons. While infants tend to wheeze more often than adults, only one third of them eventually go on to actually have asthma. Asthma and viral bronchiolitis can also be nearly identical to each other when presented in very young children, since they both consist of wheezing, coughing, and nasal congestion. In addition, typical tests used to accurately diagnose children with asthma, such as the bronchial challenge test, are not considered to be accurate for children under the age of five. This can be due to failure of very young children to cooperate. [3] [4] Diagnosing a child with asthma also carries a certain negative connotation, causing hesitancy from some physicians to do so. All of these factors lead physicians to label young children with RAD instead of asthma, since the disease is often only suspected and unable to be confirmed with pediatric patients. [2]
Physicians will generally label an adult with RAD if they have no prior diagnosis or history of asthma while exhibiting symptoms of wheezing, production of sputum, and/or the use of an inhaler. [2] Symptoms may also include, but are not limited to, coughing, shortness of breath, excess mucus in the bronchial tube, swollen mucous membrane in the bronchial tube, and/or hypersensitive bronchial tubes.[ medical citation needed ] In order to make a formal asthma diagnosis in adult patients, there is requirement to have documentation of either airway hyperreactivity or some sort of reversible airway obstruction. If none of these symptoms are present in an adult patients' medical history or documentation, the physician may label the patient with RAD instead of asthma in order to still indicate there is an airway issue without formal diagnosis. [1]
While the acronyms are similar, reactive airway disease (RAD) and reactive airways dysfunction syndrome (RADS) are not the same. [1]
Reactive airways dysfunction syndrome was first identified by Stuart M. Brooks and colleagues in 1985 as an asthma-like syndrome developing after a single exposure to high levels of an irritating vapor, fume, or smoke. [1] [5] It can manifest in adults with exposure to high levels of chlorine, ammonia, acetic acid, or sulphur dioxide, creating symptoms like asthma. [6] These symptoms can vary from mild to fatal and can even create long-term airway damage, depending on the amount of exposure and the concentration of chlorine. Patients that have been diagnosed with RADS will likely have methacholine airway hyperreactivity, yet other tests that also measure pulmonary functions may appear normal. [1] Some experts classify RADS as occupational asthma. Those with exposure to highly irritating substances should receive treatment to mitigate harmful effects. [7] Treatment for RADS is similar to treatment for other disorders that result from acute inhalation. Preexisting allergies can be a risk factor for developing RADS. [8]
The main difference between RAD and RADS is that RADS can occur after just one exposure to the inhalants and without any prior sensitization. In addition, although the symptoms of RADS are very similar to those of asthma, they may be resolved. While some physicians argue that RADS is also not a real clinical syndrome, it is more commonly recognized in legitimate associations than RAD. These associations include the American Thoracic Society and the American College of Chest Physicians. [1]
There remains controversy over the use of RAD as an unofficial diagnosis. With its use not only being limited to clinical lexicon, but also transitioning to clinical literature now, more physicians are now increasingly disapproving its use in the healthcare setting. [1]
One of the largest problems with the using RAD as a diagnostic label lies in the ambiguity of its meaning, as RAD has no true clinical definition. [1] It is either not listed or redirects to "asthma" in all major medical journal or website. In addition to that, it is also not recognized in the American Academy of Pediatrics; the American Thoracic Society; or the National Heart Lung and Blood Institute. [3] In addition, treatments for asthma, chronic bronchitis, emphysema, or pneumonia may not be prescribed under a label of reactive airway disease. [1] In contrast, some physicians also fear overtreatment for RAD, as patients can be prescribed inhaled beta-agonists or inhaled corticosteroids, which are medications used for asthma. If an individual with RAD doesn't have asthma, there is no evidence these treatments are beneficial. [1] As a result of its ambiguous place in the medical field, the symptoms used to characterize it are often inconsistent and can lead to confusion in a healthcare setting. This is a troubling issue for many physicians, as care can be made more complicated; many patients labeled with RAD do not ultimately have asthma and most RAD patients have never formally had their airway reactivity measured. [1]
In addition to the inconsistencies of its labeling, there is also no billing designation for RAD in the International Statistical Classification of Diseases and Related Health Problems, or the ICD, which can lead to problems for healthcare facilities. Searches in the ICD, point to content relating to asthma. [3] Some medical professionals argue that using RAD as a diagnosis will only complicate research on asthma in the context of clinical research and epidemiology. There is also dispute that by giving physicians the ability to label a patient with RAD, it gives them a fabricated sense of security that they have made a diagnosis, when no real recognizable diagnosis has been concluded. [1]
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise.
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.
Acute bronchitis, also known as a chest cold, is short-term bronchitis – inflammation of the bronchi of the lungs. The most common symptom is a cough. Other symptoms include coughing up mucus, wheezing, shortness of breath, fever, and chest discomfort. The infection may last from a few to ten days. The cough may persist for several weeks afterward with the total duration of symptoms usually around three weeks. Some have symptoms for up to six weeks.
Bronchiectasis is a disease in which there is permanent enlargement of parts of the airways of the lung. Symptoms typically include a chronic cough with mucus production. Other symptoms include shortness of breath, coughing up blood, and chest pain. Wheezing and nail clubbing may also occur. Those with the disease often get lung infections.
A wheeze is a clinical symptom of a continuous, coarse, whistling sound produced in the respiratory airways during breathing. For wheezes to occur, some part of the respiratory tree must be narrowed or obstructed, or airflow velocity within the respiratory tree must be heightened. Wheezing is commonly experienced by persons with a lung disease; the most common cause of recurrent wheezing is asthma, though it can also be a symptom of lung cancer, congestive heart failure, and certain types of heart diseases.
Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun.
Acute severe asthma, also known as status asthmaticus, is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators (inhalers) and corticosteroids. Asthma is caused by multiple genes, some having protective effect, with each gene having its own tendency to be influenced by the environment although a genetic link leading to acute severe asthma is still unknown. Symptoms include chest tightness, rapidly progressive dyspnea, dry cough, use of accessory respiratory muscles, fast and/or labored breathing, and extreme wheezing. It is a life-threatening episode of airway obstruction and is considered a medical emergency. Complications include cardiac and/or respiratory arrest. The increasing prevalence of atopy and asthma remains unexplained but may be due to infection with respiratory viruses.
Exercise-induced asthma (E.I.A.) occurs when the airways narrow as a result of exercise. The preferred term for this condition is exercise-induced bronchoconstriction (EIB). While exercise does not cause asthma, it is frequently an asthma trigger.
Feline asthma is a common allergic respiratory disease in cats, affecting at least one percent of all adult cats worldwide. It is a chronic progressive disease for which there is no cure. Common symptoms include wheezing, coughing, labored breathing and potentially life-threatening bronchoconstriction. There is conjecture that the disease has become more common due to increased exposure to industrial pollutants. Feline asthma can also be attributed to lung damage caused by long-term exposure to second-hand smoke.
A habit cough is a chronic cough that has no underlying organic cause or medical diagnosis, and does not respond to conventional medical treatment. This is sometimes called tic cough,somatic cough syndrome and previously psychogenic cough, but without clinical justification.
The use of podiatry drills, in the absence of engineering controls and personal protective equipment, is an occupational hazard to the healthcare provider. Nail dust collected during foot care procedures performed in office settings has been found to contain keratin, keratin hydrolysates, microbial debris, and viable fungal elements, including dermatophytes and saprotrophs. Exposure to nail dust and the associated risk will vary with the policies and practices in place, the type of podiatry drill used, therapy technique, frequency of procedures, personal protective equipment utilized and the use of ventilation systems.
Occupational asthma is new onset asthma or the recurrence of previously quiescent asthma directly caused by exposure to an agent at workplace. It is an occupational lung disease and a type of work-related asthma. Agents that can induce occupational asthma can be grouped into sensitizers and irritants.
Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. Many obstructive diseases of the lung result from narrowing (obstruction) of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, problems exhaling, and frequent medical clinic visits and hospitalizations. Types of obstructive lung disease include; asthma, bronchiectasis, bronchitis and chronic obstructive pulmonary disease (COPD). Although COPD shares similar characteristics with all other obstructive lung diseases, such as the signs of coughing and wheezing, they are distinct conditions in terms of disease onset, frequency of symptoms, and reversibility of airway obstruction. Cystic fibrosis is also sometimes included in obstructive pulmonary disease.
Vocal cord dysfunction (VCD) is a pathology affecting the vocal folds characterized by full or partial vocal fold closure causing difficulty and distress during respiration, especially during inhalation.
Eosinophilic bronchitis (EB) is a type of airway inflammation due to excessive mast cell recruitment and activation in the superficial airways as opposed to the smooth muscles of the airways as seen in asthma. It often results in a chronic cough. Lung function tests are usually normal. Inhaled corticosteroids are often an effective treatment.
Tropical pulmonary eosinophilia, is characterized by cough, bronchospasm, wheezing, abdominal pain, and an enlarged spleen. Occurring most frequently in the Indian subcontinent and Southeast Asia, TPE is a clinical manifestation of lymphatic filariasis, a parasitic infection caused by filarial roundworms that inhabit the lymphatic vessels, lymph nodes, spleen, and bloodstream. Three species of filarial roundworms, all from the Onchocercidae family, cause human lymphatic filariasis: Wuchereria bancrofti, Brugia malayi, and Brugia timori.
Stuart Merrill Brooks is an American pulmonary doctor who is credited for discovering and researching Reactive Airways Dysfunction Syndrome (RADS) to describe an asthma-like syndrome developing after a single exposure to high levels of an irritating vapor, fume, or smoke. It involves coughing, wheezing, and dyspnea. Dr Brooks received the highest honor in occupational and environmental medicine, the Knudsen Award. This award recognizes an individual who has made outstanding contributions to the field. Dr Brooks was honored for his exemplary efforts in starting the first occupational medicine residency in Florida in 1982.
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a diffuse parenchymal lung disease which often presents with symptoms of cough and shortness of breath. The pathological definition published by the World Health Organization is “a generalized proliferation of scattered single cells, small nodules, or linear proliferations of pulmonary neuroendocrine (PNE) cells that may be confined to the bronchial and bronchiolar epithelium.” The true prevalence of this disease is not known. To date, just under 200 cases have been reported in the literature. However, with an increase in recognition of this disease by radiologists and pulmonologists, the number of cases has been increasing. DIPNECH predominantly affects middle-aged women with slowly progressive lung obstruction. DIPNECH is usually discovered in one of two ways: 1) as an unexpected finding following a lung surgery; or 2) by evaluation of a patient in a pulmonary clinic with longstanding, unexplained symptoms.
Plastic bronchitis (PB) is a disorder in which branching casts of the airways are expectorated. PB is not a single disease with a defined mechanism that explains the cast formation in all conditions. Examples of diseases associated with expectoration of casts, and which sometimes are labeled PB include tuberculosis, atypical mycobacterial disease, allergic bronchopulmonary aspergillosis, and asthma.
Chronic cough is long-term coughing, sometimes defined as more than several weeks or months. Generally a cough lasting for more than eight weeks for an adult would meet the clinical definition of a chronic cough; and for children this threshold is lower. The term can be used to describe the different causes related to coughing, the three main ones being upper airway cough syndrome, asthma and gastroesophageal reflux disease. It occurs in the upper airway of the respiratory system. Generally, a cough lasts around one to two weeks; however, chronic cough can persist for an extended period of time defined as six weeks or longer. People with chronic cough often experience more than one cause present. Due to the nature of the syndrome, the treatments used are similar; however, there are a subsequent number of treatments available, and the clinical management of the patients remains a challenge.