From: Fungal allergy in asthma–state of the art and research needs
Test | Strengths | Weaknesses | Comment |
---|---|---|---|
Skin prick test (SPT) | Simple to perform. Rapid results. Good tolerability. Inexpensive. High negative predictive value (95%) | Accuracy and reliability dependent on quality of fungal extracts. Variability between different batches of test. | Test should be performed with standardised allergen solution, if possible. Best used in conjunction with sIGE due to discordance in results. |
Misses low sensitivity responses. | |||
Systemic and topical antihistamines may suppress weal and flare reaction. Presence of IgE without clinical symptoms. | |||
Intradermal tests | More sensitive than SPT. | Higher rate of false positives than SPT. | Rarely used. |
IgE (ImmunoCAP)a | Completely safe. Not influenced by concurrent drug treatment. | Results not immediately available. Testing more expensive than SPT. Presence of IgE without clinical symptoms. | Best used in conjunction with SPT due to discordance in results. |
Complete blood count | Automated test. | Many different conditions result in increases or decreases in cell populations. Lack of correlation between peripheral blood eosinophil levels and lung function / immunological parameters. | Performed to assess peripheral blood eosinophil levels. |
Fungal culture of sputum | Simple to perform. Inexpensive. | Lack of standardisation in most countries. UK standard insensitive. | Actively growing culture needed for strain-typing or anti-fungal sensitivity |
Fungal PCR of sputum | More sensitive than culture. | May have high false-positives. Requires specialised equipment, although most labs have PCR machines. | Commercial tests available but no accepted standard for positivity. |