Page 97 - Škrgat, Sabina, ed. 2022. Severe Asthma - Basic and Clinical Views. Koper: University of Primorska Press. Severe Asthma Forum, 1
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ine-aspirin is as sensitive as oral one, but during provocation testing. It is also recom- 97
safer and faster to perform11. mended that if AERD is suspected, spirome-
try or at least a PEF measurement should be asthma and aspirin exacerbated respiratory disease
Nasal provocation is useful in patients performed before the next dose. The test is
with severe and unstable asthma and is at positive if at least one or more objective symp-
higher risk for severe obstruction. On the oth- toms are present, such as upper respiratory
er hand, it is not useful in patients with se- tract reaction (rhinorrhoea, nasal congestion,
vere nasal obstruction due to massive nasal sneezing, lacrimation), bronchospasm (dysp-
polyposis as this reduces the sensitivity of the noea, wheezing), laryngospasm, a drop of
test26. At first, the test should be done with in- 20% in FEV1 or PEF. At the slightest symp-
tranasal saline to exclude unspecific hyper- tom onset, the test should be stopped immedi-
sensitivity. Then lysine aspirin up to 80 uL is ately and treated aggressively with antihista-
installed into each nostril33. Assessment of the mines, nasal decongestants, bronchodilators,
reaction includes a combination of objective and adrenaline. There are several different
symptoms such as rhinorrhea, sneezing, na- protocols for oral aspirin provocation. The in-
sal congestion, and objective reduction of na- itial dose is typically 10-20 mg. The number
sal flow measured with acoustic rhinometry, of steps also varies, mostly in 5-8 steps. When
active anterior rhinomanometry, and peak AERD is suspected, it is important to remem-
nasal inspiratory flow33. As the sensitivity of ber that a reaction can occur up to 3 hours
nasal provocation is low, negative test should after the aspirin dose and therefore a longer
be followed by oral provocation. Oral provo- observation period is required. In contrast
cation test is considered the gold standard in to immediate IgE-mediated hypersensitivi-
drug hypersensitivity. Although it has a high ty testing where reactions usually occur im-
specificity, it still does not have 100% sensi- mediately or within the first hour after drug
tivity, so in some cases, even a negative prov- administration, so observation up to 2 hours
ocation test cannot completely rule out drug after the last dose is usually sufficient. There-
hypersensitivity. Drug provocation test is fore, most protocols provide for a 2-day prov-
time-consuming, complicated, and potential- ocation protocol with aspirin. The median
ly dangerous. It needs to be performed in a sit- cumulative dose at which symptoms occur is
uation where emergency treatment is availa- 68-157 mg34,35. Upper respiratory tract symp-
ble, as well as intensive care unit. Medications toms and lacrimation are usually the first to
for anaphylaxis, adrenaline, and antihista- occur. Bronchospasm is described in 35-90%.
mines should be available on site. It should In addition to these, gastrointestinal symp-
be performed under the supervision of expe- toms (abdominal pain, nausea, vomiting),
rienced and trained personnel. When select- skin signs (erythema, pruritus, urticaria), and
ing an appropriate protocol for drug testing, it even hypotension have been described26,36.
should be borne in mind that inadvertent de-
sensitization to the drug may occur during the Risk factors predicting a more severe
test, resulting in a false-negative result. There- bronchial reaction include: patients not re-
fore, the doses and the interval between doses ceiving additional anti leukotriene therapy,
should be carefully selected. Ideally, the inter- AERD symptoms lasting less than 10 years,
val between doses of an oral drug provocation reduced FEV1 already before the start of test-
test should be 60 min and the amount of drug ing, history of asthma exacerbations requiring
administered should be at least 2 times, but an emergency room visit37. There are also pa-
preferably 10x the previous dose. tients with a high clinical pretest probability
of AERD but in whom the aspirin challenge
Vital parameters, blood pressure, pulse, test is negative. According to some ­studies, the
and saturation should be carefully monitored
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