Vol 43 # 2 June 2011 - Kma.org.kw

June 2011
KUWAIT MEDICAL JOURNAL 111
Fig. 5: Population distribution according to age & sex
Fig. 7: Diagnosis in relation to age
Fig. 3 shows the number of patients who had
positive reactions to more than one allergen. This data
shows the possibility of cross-reaction of one allergen
with other pollen sensitization like Prosopis and / or
date tree. The degree of allergic reaction in relation
to age group of patients tested is presented in Fig. 4.
The severe positive reaction of allergens was noted in
the age group 3 - 6 yrs old (31.8%) and moderate for
the age group 0 - 3 yrs (23.6%) and > 10 yrs (24.5%).
Mild reactions were seen in age group 6 - 10 yrs (20%).
Fig. 5 shows the distribution of patients according to
age and sex. Out of 110 patients, 46% were children
and 55% were adults; 64% female and 37% male. Fig.
6 shows that most of the patients tested (both adults
and children) had history of allergies. Fig. 7 shows
that most of the patients diagnosed were positive for
allergic rhinitis and asthma with adults having the
most positive results.
DISCUSSION
To date, there are very limited studies reported
on sensitization to Prosopis. However, international
reports published from a few countries strongly
suggest sensitivity factors to airborne prosopis pollen.
As such, future researches or testing should be carried
out on Prosopis-induced asthma and other allergies in
the region.
Recently, P. juliflora pollen allergens (family:
Leguminosae) with other tree species has also been
delineated [11] , but efforts are required to investigate
cross-allergenicity of foods and pollen belonging to
the legume botanical family. This is also indicative of
Fig. 6: Family history of allergic patients in relation to age
availability of allergen sources (Prosopis pollen) and
their impact and / or ability to induce allergic reaction
in and around the region. This finding is supported
by the work of Novey et al [3] , who trapped Prosopis
pollen from a considerable distance from its source in
California. Several common foods like chickpea, green
gram, egg white, and bean fresh / red gram have
been reported to cause allergenicity and concomitant
sensitization in several patients [12] . By conducting
diagnostic tests on 100 consecutive patients using 30
pollen antigens, they obtained 42% positive on scratch
test and an additional 20% positive intradermal test to
Prosopis extracts. He concluded that mesquite pollen
is a potent allergen capable of evoking immediate
hypersensitivity reactions in a susceptible population
remote from the plant source. Lucas and Buckley [4] also
studied the prevalence of epicutaneous flare reactions
to allergenic pollen including mesquite, and concluded
that it is mesquite which exhibits the most informative
positive reaction.
The findings of this study revealed that (a) airborne
pollen allergy is a major factor which can contribute
to asthma and other respiratory diseases; (b) a higher
positive reaction (75.5%) to prosopis in patients was
noted using SPT diagnosis; (c) date tree pollen allergy
might cross-react with prosopis (54.5%) as shown in
SPT results; (d) other allergens which had positive
SPT results should also be given attention like CAT
epithelium (46.4%), bermuda grass (66.4%), Russian
thistle (71%) and Atriplex which can also cause crossreactivity
among tree pollens and not necessarily to
prosopis pollen.
The SPT results presented wherein a higher positive
reaction to Prosopis juliflora extract were obtained,
indicate that patients are sensitized with specific IgE
Table 1: Illustrates the standard scale of SPT
Saline / Histamine
Saline/Glycerine
Histamine
Same as histamine
< histamine > Saline
> histamine
Only ≥ is considered positive
0
3+
3+
Standard Scale
2+ (1/2 histamine size)
4+