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| {{SI}}
| | #redirect [[Aspergillosis]] |
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| ==Overview==
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| '''Allergic bronchopulmonary aspergillosis''' ('''ABPA''') is a hypersensitivity response to the fungus ''[[Aspergillus fumigatus]]'', the spores of which are ubiquitous in soil and are commonly found in the sputum of healthy individuals. [[Aspergillus fumigatus|''A. fumigatus'']] is responsible for a spectrum of lung diseases commonly grouped under the heading of [[aspergillosis|aspergilloses]].
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| ==Epidemiology==
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| Estimating the prevalence of ABPA has been made difficult by lack of uniform diagnostic criteria and standardised tests. It usually occurs as a complication of other chronic lung disease, in particular [[asthma]] or [[cystic fibrosis]]. It is estimated that in the US ABPA may be present in between 0.5 and 2% of all [[asthma]] patients.
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| ==Immunology and pathophysiology==
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| There is both a [[type I hypersensitivity|type I]] ([[atopy|atopic]]) and [[type III hypersensitivity]] response. Precipitating antibodies incite a type I acute hypersensitivity reaction with release of immunoglobulin E (IgE) and immunoglobulin G (IgG), resulting in [[mast cell]] [[degranulation]] with [[bronchoconstriction]] and increased capillary permeability. Immune complexes and inflammatory cells are then deposited within the bronchial mucosa leading to tissue necrosis and eosinophilic infiltrate, a type III reaction. The subsequent damage to the bronchial wall causes (proximal) [[bronchiectasis]].
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| Repeated acute episodes left untreated can result in progressive pulmonary [[fibrosis]] that is often seen in the upper zones and can give rise to a similar radiological appearance to that produced by [[tuberculosis]].
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| The main features are therefore:
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| *bronchospasm
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| *increased mucus production and plugging of distal airways, leading to their collapse
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| *[[bronchiectasis]]
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| ==Clinical picture==
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| ===Symptoms===
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| *[[wheeze]]
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| *[[cough]]
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| *[[fever]]
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| *[[malaise]]
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| *recurrent [[pneumonia]] (eosinophilic, therefore not responding to antibiotics)
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| *expectoration of mucoid plugs (containing the fungal hyphae)
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| *unexplained worsening of [[asthma]] or [[cystic fibrosis]]
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| ===Investigations===
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| A full blood count usually reveals [[eosinophilia]] more than 10% and there is a raised serum IgE more than 1000ng/ml.
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| ''Chest radiography'' shows various transient abnormalities:
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| *consolidation or collapse
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| *thickened bronchial wall markings
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| *peripheral shadows
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| *signs of central [[bronchiectasis]]
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| ''Aspergillus specific tests'':
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| *precipitating antibodies to aspergillus species in >90% of cases
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| *aspergillus-specific IgE [[RAST test]]
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| *skin-prick test is almost always positive to Aspergillus fumigatus
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| ==Management==
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| The aim of treatment is to suppress the immune reaction to the fungus and to control bronchospasm.
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| The immune reaction is suppressed using oral [[corticosteroids]]:
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| *a high dose of [[prednisolone]] or [[prednisone]] (30 to 45 mg per day) in acute attacks
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| *a lower maintenance dose (5-10 mg per day)
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| Mucus plugs may be removed by bronchoscopic aspiration. It is almost impossible to eradicate the fungus but sometimes [[itraconazole]] (an anti-fungal) is used in combination with steroid therapy. Regular monitoring of the condition includes chest x-rays, [[spirometry|pulmonary function tests]], and serum IgE. The antibody levels usually fall as the disease is controlled, but they may rise again as an early sign of flare-ups.
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| ==Related Chapters==
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| *[[Aspergillosis]]
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| *[[Asthma]]
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| *[[Cystic fibrosis]]
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| *[[Bronchiectasis]]
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| ==References==
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| {{reflist|2}}
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| *{{cite book | last = Kumar | first = Parveen | title = Clinical Medicine | publisher = W.B. Saunders | location = Philadelphia | year = 1998 | isbn = 0702020192 }}
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| *{{cite book | last = Longmore | first = Murray | title = Oxford Handbook of Clinical Medicine | publisher = Oxford University Press | location = Oxford Oxfordshire | year = 2004 | isbn = 0198525583 }}
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| *{{cite journal |author=Greenberger PA, Patterson R |title=Allergic bronchopulmonary aspergillosis and the evaluation of the patient with asthma |journal=J. Allergy Clin. Immunol. |volume=81 |issue=4 |pages=646-50 |year=1988 |pmid=3356845}}
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| *V.P.Kurup, B.Banerjee, P.A.Greenberger, J.N.Fink. ''Allergic Bronchopulmonary Aspergillosis: Challenges in Diagnosis''. From Medscape General Medicine. [http://www.medscape.com/viewarticle/408747_1/ full text]
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| ==External links==
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| *[http://www.medscape.com/viewarticle/408747_1/ Medscape. ABPA: Challenges in Diagnosis] (free registration required)
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| *[http://www.gpnotebook.co.uk/simplepage.cfm?ID=1100611584 GP notebook. ABPA]
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| *[http://www.merck.com/mmhe/sec04/ch051/ch051d.html Merck. APBA]
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| *[http://rad.usuhs.mil/medpix/medpix.html?mode=caption_search&srchstr=allergic+bronchopulmonary+aspergillosis#top/ Medpix. ABPA radiology pictures]
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| {{Template:Allergic conditions}}
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| [[Category:Aspergillus]]
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| [[Category:Fungal diseases]]
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| [[de:Allergische bronchopulmonale Aspergillose]]
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| [[fr:Aspergillose bronchopulmonaire]]
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