Brittle asthma
Brittle asthma | |
---|---|
Asthma (lungs) | |
Prevention | Allergen avoidance and self-management approach |
Brittle asthma is a type of asthma distinguishable from other forms by recurrent, severe attacks.[1][2][3] There are two subtypes divided by symptoms: Type 1 and Type 2,[4] depending on the stability of the patient's maximum speed of expiration, or peak expiratory flow rate (PEFR). Type 1 is characterized by a maintained wide PEF variability despite considerable medical therapy including a dose of inhaled steroids, and Type 2 is characterized by sudden acute attacks occurring in less than three hours without an obvious trigger on a background of well controlled asthma.[5]
Brittle asthma is one of the "unstable" subtypes of "difficult asthma", a term used to characterize the less than 5% of asthma cases that do not respond to maximal inhaled treatment, including high doses of corticosteroids combined with additional therapies such as long-acting beta-2 agonists.[6][7]
Diagnosis
Types
The 2005
When first defined by Margaret Turner-Warwick in 1977, the term brittle asthma was used specifically to describe type 1, but as studies into the phenotype were conducted the second type was also distinguished.[11]
Treatment
In addition to any issues of
Epidemiology
The condition is rare. 1999's Difficult Asthma estimates a prevalence of approximately 0.05% brittle asthma sufferers among the asthmatic population.[14] Though found in all ages, it is most commonly found in individuals between the ages of 18 and 55; it is present in both sexes, though type 1 has been diagnosed in three times as many women as men.[14] Hospitalization is more frequent for type 1 than type 2.[14]
References
- ISBN 1-85317-556-0.
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- ISBN 0-19-856978-5.
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- ^ a b Warrell, 1347.
- ^ Saunders (2005). "Asthma". In Homer A. Boushey Jr., M.D.; David B. Corry, M.D.; John V. Fahy, M.D.; Esteban G. Burchard, M.D.; Prescott G. Woodruff, M.D.; et al. (eds.). Mason: Murray & Nadel's Textbook of Respiratory Medicine (4th ed.). Elsevier.
- ^ Holgate et al., 292.
- ISBN 978-0-470-03000-4.
- PMID 15636398.
- PMID 17695694.
- ^ a b c Holgate et al., 293.