Page 68 - Portuguese Journal - SPORL - Vol 61. Nº1
P. 68
Six months after IT, there was a reduction in that this method was as useful, specific,
patients’ symptoms (nasal, ocular, and lung sensitive, and reproducible as testing with a
symptoms) and use of emergency medica- single allergen, as well as less time-consuming.
tion, as well as a greater tolerance to allergens In addition, they demonstrated that NAPTm
and improved quality of life. The success of IT is in total agreement with the results of
in LAR is associated with an increase in the se- the NAPT and is safe, with no exacerbated
rum levels of specific IgG and a decrease in inflammatory response compared to the
4
IgE in the nasal secretions. However, it has not NAPT. In a previous study by Wierzbicki et al. ,
25
been reported whether the use of IT in LAR in which a panel of multiple allergens was also
modifies the clinical course of the disease . used in the NAPT for the diagnosis of LAR in
16
patients initially classified as perennial NAR,
Discussion there were seven false positive results. These
The diagnosis of AR is based on the clinical discordant results may be explained by the
history, positive response in SPT, and positive use of a different control solution (may trigger
serum specific IgE. However, a structured a nasal irritant response) or by the fact that the
clinical history along with directed sIgE test was performed in only one nasal cavity.
increases the diagnostic precision in AR, Some allergen solutions contain preservatives
compared with clinical history alone. that react with the nasal mucosa and it is thus
However, this diagnostic approach does not essential to have control by conducting a test
allow the diagnosis of LAR in which the SPT with the dilution solution in the nasal mucosa
and sIgE are negative, and it is thus necessary to exclude nasal hyperreactivity .
19
to perform the NAPT . The fact that the On the other hand, in their protocol, Wierzbicki
2-6
patients diagnosed with LAR already have an et al. also used a concentration of allergen
25
extended follow-up and monitoring period, (namely D. pteronyssinnus) lower than that
without progression to AR, supports the recommended to trigger a positive response
notion that LAR is a separate entity from AR, in the nasal mucosa. Although NAPTm is
despite the similar symptoms and therapeutic essential for the diagnosis of patients with
response . Some authors advocate IgE testing LAR who are mono- and polysensitized to
8
in nasal secretions during natural exposure to allergens, it is not possible to measure the
allergens or after the NAPT because the in vitro intensity of the nasal allergic response. This is
detection of sIgE has high specificity, despite only possible through a NAPT with a gradual
having low sensitivity (between 22% and increase in the concentration of the allergen
40%). Its low sensitivity may be explained by administered during the provocation until a
the effect of dilution, a non-specific response target concentration that triggers the allergy
to house mites, or other not yet identified symptoms is reached .
3-4
factors . Given its low sensitivity, IgE detection For the evaluation of the response to NAPT,
8
in nasal secretions is not a good method several scales exist that facilitate the subjective
for the diagnosis of LAR and is reserved for assessment of allergy symptoms.
research purposes 3-4,16 . The classification of the response may
The NAPT is a very useful diagnostic tool as it is be based on the patient’s report of nasal
more sensitive than other diagnostic methods symptoms, such as the Likert scale (0 –
such as the detection of sIgE, tryptase, ECP, none, 1 – mild, 2 – moderate, 3 – severe) or
or the basophil activation test, although its the visual analogue scale (VAS) may be used
execution is time consuming . for reporting the severity of the symptoms
3-6
Rondón et al. defined a protocol for the (mild: 0-30 mm; moderate: 31-70 mm; severe:
15
testing of several allergens in a single session 71-100 mm). The Total Nasal Symptom Score
(NAPTm), using a panel of four allergens most (TNSS) is a scale that assesses four symptoms
commonly involved in LAR. They concluded (rhinorrhea, nasal congestion, sneezing, and
68 Portuguese Journal of Otorhinolaryngology - Head and Neck Surgery
