Nevertheless, between 40 and 60% of patients do have positive cultures depending on the number of samples taken. Staging
New criteria by the ABPA Complicated Asthma ISHAM Working Group suggests a 6-stage criteria for the diagnosis of ABPA, though this is yet to be formalised into official guidelines. This would replace the current gold standard staging protocol devised by Patterson and colleagues. Stage 0 would represent an asymptomatic form of ABPA, with controlled asthma but still fulfilling the fundamental diagnostic requirements of a positive skin test with elevated total IgE (>1000 IU/mL). Stage 6 is an advanced ABPA, with the presence of type II respiratory failure or pulmonary heart disease, with radiological evidence of severe fibrosis consistent with ABPA on a high-resolution CT scan. It must be diagnosed after excluding the other, reversible causes of acute respiratory failure. Treatment
Underlying disease must be controlled to prevent exacerbation and worsening of ABPA, and in most patients this consists of managing their asthma or CF. Any other co-morbidities, such as sinusitis or rhinitis, should also be addressed.Hypersensitivity mechanisms, as described above, contribute to progression of the disease over time and, when left untreated, result in extensive fibrosis of lung tissue. In order to reduce this, corticosteroid therapy is the mainstay of treatment (for example with prednisone); however, studies involving corticosteroids in ABPA are limited by small cohorts and are often not double-blinded. Despite this, there is evidence that acute-onset ABPA is improved by corticosteroid treatment as it reduces episodes of consolidation.
Minimal criteria include five factors:  the presence of asthma and/or cystic fibrosis, a positive skin test to Aspergillus sp., total serum IgE > 416 IU/mL (or kU/L), an increased Aspergillus species–specific IgE and IgG antibodies, and the presence of infiltrates on a chest X-ray.ABPA should be suspected in patients with a predisposing lung disease—most commonly asthma or cystic fibrosis— and is often associated with chronic airway limitation (CAL). Patients generally present with symptoms of recurrent infection such as fever, but do not respond to conventional antibiotic therapy. Poorly-controlled asthma is a common finding, with a case series only finding 19% of ABPA patients with well-controlled asthma. Wheezing and hemoptysis (coughing up blood) are common features, and mucus plugging is seen in 31–69% of patients. Blood tests and serology
The first stage involves exposing the skin to Aspergillus fumigatus antigens; an immediate reaction is hallmark of ABPA. The test should be performed first by skin prick testing, and if negative followed with an intradermal injection. The overall sensitivity of the procedure is around 90%, though up to 40% of asthmatic patients without ABPA can still show some sensitivity to Aspergillus antigens (a phenomenon likely linked to a less severe form of ABPA termed severe asthma with fungal sensitization (SAFS)).Serum blood tests are an important marker of disease severity and are also useful for the primary diagnosis of ABPA. When serum IgE is normal (and patients are not being treated by glucocorticoid medications), ABPA is excluded as the cause of symptoms.