Pollen Allergy in Cordoba City : Frequency of Sensitization and Relation with Antihistamine Sales

Pollen allergy in Cordoba city
Original Article
Pollen allergy in Cordoba city:
frequency of sensitization and
relation with antihistamine sales
J. A. Sánchez-Mesa*, P. Serrano**, P. Cariñanos*, J. C. Prieto-Baena*, C.
Moreno**, F. Guerra**, C. Galan*
* Department of Plant Biology. University of Córdoba. Spain.
** Allergy Unit. Reina Sofia Universitary Hospital. Córdoba. Spain.
Abstract. The occurrence of symptoms in pollen allergy patients in urban areas may be affected by local
environmental factors such as sources of pollution, natural and ornamental vegetation, local architecture impeding
dispersion, etc. The aim of this study was to analyse the frequency of sensitization in pollen allergy patients and
the relationship with antihistamine sales.
For this study, a large number of clinical records, together with pharmaceutical and pollen data, were collected
between 1999 and 2001 in the city of Córdoba, in the south of the Iberian Peninsula.
Differences were observed in the symptoms suffered by pollen allergy patients in different areas of the city due to
varying local emission of both biological and non-biological particles. Temporal distribution of symptoms over
the three study years was influenced by meteorological factors, especially rainfall patterns; higher water supply to
plants was associated with increased airborne pollen concentrations.
Air pollution might be one of the main factors affecting the distribution of pollen allergy patients within the city.
Recent years have seen a worsening of symptoms and increased sensitization to urban species such as plane-trees.
Key words: Aerobiology, antihistamine sales, distribution of patients, pollen allergy, seasonal symptoms, urban
pollinosis.
Introduction
symptoms and asthma. Development of symptoms in
allergic patients may be correlated with the particular
Some reports suggest increased prevalence and
nature of their immediate environment. Studies have
severity of allergy diseases in industrialized countries
reported a relationship between increased incidence of
over the last few years [1].
allergic symptoms and the height of the patient’s urban
Seasonal allergy symptoms, which classically include
residence, due to the irregular vertical distribution of
sneezing, itching, nasal discharge, nasal congestion,
pollen grains once they are released from the plants [4].
ocular itching, redness and tear production, as well as
The presence of other traditional air pollutants (NO , SO
x
2,
itching of the palate, can have a significant impact on
CO and non-biological particle matter) also plays a major
everyday activities at work or school and during leisure
role in modifying and even increasing the allergic potential
time. In addition, there is a growing body of evidence
of pollen grains [5,6]. Other studies have related the spatial
that points to a close association between allergic
distribution of allergy patients in a given area to the
sensitization and asthma [2,3].
presence of different sources of emissions, both natural
The presence of a certain amount of pollen in the
and anthropogenic, and also to certain architectural
atmosphere may also prompt some worsening of allergic
features leading to formation of local islands [7].
© 2005 Esmon Publicidad
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56

---

51
J.A. Sánchez-Mesa, et al.
The city of Córdoba has been the subject of several
Central area: typical urban area with many buildings
aerobiological and allergy-related studies, due to several
and intense traffic, particularly during rush hours.
particular characteristics: Mediterranean climate, that
Exotics and ornamentals are used abundantly in gardens
allows flowering plants to be in bloom virtually
for shade.
throughout the year, abundant natural vegetation; a large
Clinical records of hay-fever patients were provided
variety of exotic species used as ornamentals, and
by the Allergy Unit at Córdoba´s Reina Sofia University
proximity to one of the world’s largest olive-producing
Hospital. The study initially screened all patients
areas. Most of the parameters that may influence allergy
attending the Allergy Unit in 1999, 2000 and 2001 with
symptoms in sensitive people or result in a higher
respiratory pathologies classified Class 8 of the ICD-9-
concentration of patients in a given area have already
CM diagnosis code as 493: Asthma and 477: Allergic
been considered [8,9], however, sales of antihistamines
rhinitis. Patients were mostly from the province of
in the various districts of the city, used as an indicator
Córdoba and other areas of Andalusia. A population
of patient background, has not hitherto been addressed.
sample was selected from this preliminary group
The aim of this study was to analyse the spatial and
including all those patients habitually resident in the
temporal distribution of allergy patients within the city,
urban area of the city of Córdoba, according to the postal
and all the parameters affecting this distribution, using
address appearing in the records. Thus, the preliminary
a large number of clinical records, together with
pool of 6,103 patients was reduced to 2,444 charts,
pharmaceutical and pollen data, collected between 1999
corresponding to patients resident in the city of Córdoba;
and 2001. It is hoped that the results obtained might
of these, 983 tested 2+ or higher to skin-prick tests with
allow allergy specialists to plan treatments and allergy
commercial aeroallergen extracts (Chenopodium album,
sufferers to plan their activities. The conclusions could
Lolium perenne, Cynodon dactylon, pollen IV (Dactylis,
be applied to other cities of similar characteristics in
Festuca, Lolium, Phleum and Poa), Olea europaea,
southern Spain.
Plantago lanceolata, Parietaria judaica from ALK
Abelló, Madrid, Spain; Helianthus annus from Bial
Aristegui, Bilbao, Spain; Platanus hybrida from C.B.F.
Leti, Barcelona, Spain) standardized in Biological units
Methods
(BU) and containing 10 mg/ml histamine phosphate as
The study was performed in the city of Córdoba
(4º45´W, 37º50´), south-western Iberian Peninsula.
Córdoba is a medium-sized city with 316,516 inhabitants
and a surface area of 50 km2; there is little industrial
development in the area, although several industrial
estates have settled in the outskirts. Farming,
predominantly olive and rain-fed cereal crops, is the core
of the local economy. The climate is influenced by the
Mediterranean sea, the annual average temperature is
17.6ºC and total annual rainfall 536 mm (according to
records of the Spanish National Institute of Meteorology
for the last 30 years).
Five districts were defined in the city according to
various characteristics, including similarity of urban
architecture and presence of natural/ornamental vegetation
(Figure 1). The districts studied were the following:
Northern area: suburban area, comprising numerous
buildings and a high prevalence of species used as
ornamentals in private gardens, and also natural
Mediterranean vegetation in the nearby mountains.
Southern area: semi-rural, semi-urban area
comprising both densely built-up zones and open spaces.
Vegetation comprises natural riverbank plants, ornamental
plants and crops surrounding the city.
Eastern area: this is the most populated and the most
industrialized area. There is some grassland and crops.
Western area: open rural area with few buildings and
one industrial site. There is a prevalence of rain-fed crops
and weeds, with a certain amount of natural Mediterranean
vegetation (holm oak woods), and ornamental species.
Figure 1. Division of areas within the city.
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56
© 2005 Esmon Publicidad

---

Pollen allergy in Cordoba city
52
Table 1. Main characteristics of the districts.
Surface
Pollen allergic
Allergic patients/
Zone
Districts
Residents
(km2)
patients
inhabitants (x10-3)
North
1,6
16.28
97350
255
2.6
South
9
4.62
42798
151
3.5
East
2,5
18.82
101389
366
3.6
West
10
8.96
55167
172
3.1
Centre
3,4,7,8
1.32
19812
39
1.9
Total
50.00
316516
983
3.1
a positive control. The patients’ postal addresses enabled
Lastly, the percentage of sensitization to the different
them to be grouped according to their residential zones,
pollen types was compared with those from a previous
following the zonal distribution established by the
study carried out in the city of Cordoba from 1984 to
Spanish National Institute of Statistics (INE). Time spent
1990 in order to find out differences.
in the various districts was also estimated: 41.6% of
patients spent most of the day in the same district
whether at home, school or work; 21.3% moved to other
Results
parts of the city during working hours and the remainder
had no routine habits [8].
Table 1 shows the main characteristics of the districts.
Data on monthly sales of 50 common antihistamines
Taking into account the city as a whole, the percentage
during 1999, 2000 and 2001 were used in order to
of male and female patients was very similar (47.3 v.
determine indirectly the temporal symptoms in allergy
52.7). Most of the patients (63.2% of the total) were
sufferers. The antihistamines considered in this study
aged between 11 and 30 years old.
were suggested by the Allergy Unit at Córdoba´s Reina
Table 2 shows the prevalence of allergic reactions to
Sofia Hospital; all of them include one of the following
different pollen types from the standard battery used in
active pharmaceutical ingredients: azelastine
skin prick-tests in each area. Olea and Poaceae affected
hydrochloride, cetirizine hydrochloride, ebastine,
the highest percentage of patients in the five districts.
levocabastine, loratadine, emedastine, ketotifen,
Platanus and Parietaria were among the least important
mizolastine, dexchlorpheniramine and fexophenadine
causes of allergy in the resident population. The eastern
hydrochloride. Data on antihistamine sales have been
and southern areas showed the highest prevalence of
grouped taking into account the area where they were
allergy, whereas the central area showed the lowest one.
bought, in order to calculate antihistamine units sold by
Fig 2 shows monthly antihistamine units sold in the
area and antihistamine units sold in each area by number
city of Córdoba, units sold by area and units sold in each
of inhabitants.
area by number of inhabitants between 1999 and 2001. All
Airborne pollen concentrations were measured using
areas showed a similar tendency but, as shown by the third
a stationary Hirst-type volumetric sampler. The trap was
graph, the highest number of antihistamine units sold per
located at a height of 15 metres above ground level,
inhabitant was recorded in the central area. In the first
following Aerobiology guidelines, on the flat roof of
graphs of antihistamine sales, a considerable peak during
the School of Pedagogy in the western area (position
months with highest airborne pollen concentrations, i.e.
shown on map). The daily samples obtained from the
from March to June, has been observed. This is clearly
Hirst-type sampler were analysed using the standard
related to the seasonal allergy period.
methodology proposed by the Spanish Aerobiology
Table 3 shows correlations between monthly pollen
Network [10].
indices and monthly antihistamine sales between 1990
Spearman´s correlation test was performed to
and 2001. A significant positive correlation was found
determine the relationship between monthly pollen
for Plantago, Platanus, Poaceae and Olea. In contrast,
indices and monthly antihistamine sales between 1999
a poor, non-significant correlation was observed for
and 2001.
Parietaria, Chenopodium and Helianthus.
© 2005 Esmon Publicidad
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56

---

53
J.A. Sánchez-Mesa, et al.
16000
D 14000
L
O
S 12000
E
I
N
M 10000
A
T
IS
8000
I
H
T
N
6000
F
A

O
S
4000
IT
N
U
2000
0
JAN
M AY
SEP
JAN
M AY
SEP
JAN
M AY
SEP
5000
A
E
R 4000
/
A
E
I
N
M 3000
A
T
IS
I
H
T
N 2000

F
A

O
S 1000
IT
N
U
0
JAN
M AY
SEP
JAN
M AY
SEP
JAN
M AY
SEP
0,06
S 0,05
NT
A
T
BI 0,04
/

I
NHA
A 0,03
RE
.
/

A
T 0,02
S
I
HI
T 0,01
AN
0
JAN
M AY
SEP
JAN
M AY
SEP
JAN
M AY
SEP
north
south
e ast
we st
ce ntre
Figure 2. Monthly antihistamine units sold in the city, units sold by area and units sold in each area by number of
inhabitants between 1999 and 2001.
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56
© 2005 Esmon Publicidad

---

Pollen allergy in Cordoba city
54
Table 2. Prevalence of allergic reactions to different pollen types in each area (x10-2).
North
West
South
Centre
East
Chenopodium
8.01
8.33
10.50
6.56
13.70
Helianthus
9.55
9.78
13.55
5.55
14.10
Poaceae
18.79
23.20
25.23
14.13
26.72
Olea
20.64
25.19
28.03
14.63
29.58
Plantago
9.24
10.15
11.21
6.05
12.52
Platanus
5.64
7.06
5.60
3.02
6.90
Parietaria
3.28
3.62
3.50
3.02
4.04
Table 3. Correlations between monthly pollen indices
Table 4. Percentage of patients displaying reactions to
and monthly antihistamine sales between 1999 and 2001.
several pollen types (%).
1984-1990
1999-2001

Spearman

Pollen type

R
Chenopodium
22.50
32.65
Olea
60.80
80.26
Plantago
0.69*
Parietaria
2.50
11.59
Platanus
0.62*
Plantago
29.16
33.87
Poaceae
0.55*
Poaceae
82.50
73.00
Olea
0.52*
Platanus
No tested
19.73
Parietaria
0.27
Chenopodium
0.15
Helianthus - 0.04
* 95% of significance.
The centre of the city had the lowest percentage of
people suffering from pollinosis. People in this area tend
to be older, due to the movement of young families
towards the outskirts of the city. A study performed
Table 4 charts the percentage of patients displaying
across Spain reported that the 14 –25 age-group was
reactions to several pollen types, comparing the results
the most affected by pollinosis [15]. The present study
of the present study with those of previous studies
shows that most pollen-allergy sufferers in the city of
performed in the city of Córdoba from 1984 to 1990 [9].
Córdoba are between 11 and 30 years old. Moreover,
people living in the central area usually attend allergy
clinics in the city centre rather than the Allergy Unit at
Discussion
Cordoba´s Reina Sofia University Hospital. Therefore,
their pollen sensitivity records would not be included in
Results suggest that the pollen types most
this study.
troublesome to allergy patients are Olea and Poaceae.
The graphs of antihistamine sales show differences
Similar findings are reported in previous studies carried
in annual sales during 1999, 2000 and 2001. Those three
out in the city of Córdoba [11], in Spain as a whole [12]
years were climatologically different: 1999 was the
and in other Mediterranean countries [13]. Within the
driest of the three and this resulted in a reduction in the
city of Córdoba, the highest incidence of pollen allergy
number of pollen grains released into the atmosphere,
occurs in the eastern and southern zones. These are the
mainly in the case of herbaceous plants. People sensitive
areas containing the bulk of the industrial sites. They
to pollen suffered from mild symptoms during this year.
also constitute the main routes in and out of the city,
In 2000 the rainfall was average. For people sensitive to
where there are frequent traffic jams. This would support
herbaceous pollens such as Poaceae, this was a moderate
the relationship already observed between pollution and
year with only a few days of high pollen concentrations.
a higher incidence of allergy [6,14].
Two peaks can be seen in 2000. The first one was related
© 2005 Esmon Publicidad
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56

---

55
J.A. Sánchez-Mesa, et al.
to high airborne Platanus pollen levels during March (a
the increasing sensitization to pollen and pollution. This
total of 9,442 grains/m3), the highest in the city for the
is aggravated by increased sensitization to Platanus
last 10 years. This caused an increase of symptoms in
pollen over recent years: due to the problems observed
people sensitive to this pollen type and in consequence,
during the flowering of this typical urban species in the
a peak in the curve of antihistamines sold. The second
city, plane-tree pollen has been included in the battery
peak was related to the usual months of higher pollen
of allergens used in skin prick tests, and is today one of
incidence. Year 2001 was very rainy, which caused an
the main allergenic pollen types in the area. One of the
increase in airborne pollen concentrations due to the
most important findings of the study is that in spite of
immediate response of herbaceous plants to water, and
the low frequency of sensitization to Platanus, the
consequently a higher number of allergy episodes. Each
correlation with the antihistamine sales is quite
of the three study years fitted one of the categories
significant, suggesting that Platanus pollen can induce
established by Sánchez Mesa et al. (2002), who
more important symptoms than other pollen types.
classified a set of 20 years in terms of meteorological
characteristics. There is an associated potential
allergenic risk depending on the class in which a year is
Acknowledgements
included [16].
All districts of the city showed similar trends for the
The authors wish to thank the Fondo de Investigación
variables studied with the exception of the center, where
Sanitaria (FIS) for the BEFI Grant Ref: 00/9406 and
a larger number of antihistamine sales per inhabitant
Córdoba´s Reina Sofia University Hospital and
was observed. This might be because allergy patients
Provincial Division for Heath, Regional Government of
usually buy medication in the city center, where most
Andalusia for data supply.
pharmacies and chemists are located. There are also two
district Public Health Services in the center, and people
often buy medicines after visiting the doctor.
A positive and significant correlation was observed
References
between monthly pollen indices and antihistamine sales
for Plantago, Platanus, Poaceae and Olea. From these
1. Bousquet J., Burney P.G.J., Blumenthal M., Burr M., Bryan
results, it may be concluded that pollination in these
S., Charpin D., Kaslow R. A., Kay B., Kjellman N.I.M.,
species coincides with major allergy episodes. The high
Mapp C., Miyamoto T., Paoletti P., Pollock J., Ronchetti R.,
values recorded for Plantago may be related to its cross-
Weeke E.R., Svendsen V.G., Szemer P., Troise C., Wahn U.,
reactivity with Poaceae [17].
Weiss K., Zweimann B., Blumenthal M. Evidence for an
increase in atopic disease and posible causes. Clin Exp
The percentage of patients sensitive to the different
Allergy 1993, 23:484-492.
pollen types has changed considerably over recent years.
2. Sporik R., Ingram J.M., Price W., Sussman J.H., Honsinger
There has been an increase regarding all pollen types
R.W., Platts-Mills T.A. Association of asthma with serum
with the exception of Poaceae. Córdoba has recently
IgE and skin test reactivity to allergens among children living
seen a reduction in the number of ecosystems where
at high altitude. Am J Respir Crit Care Med 1995, 151:1388-
grasses are able to grow, due to the expansion of the
1392.
city and to town-planning changes. Olea has increased
3. Von Mutius E., Martinez F.D., Frtzsch C., Nicolai T., Roell
G., Thiemann H-H. Prevalence of asthma and atopy in two
by almost 20 points, and it is the most important taxon,
areas of west and east Germany. Am J Respir Crit Care Med
with 80.26% of sensitive patients displaying a positive
1994, 149:358-364.
reaction. This may be due to an increase in the area given
4. Alcázar P., Galan C., Cariñanos P., Domínguez E. Effects of
over to olive-growing in the south of the Iberian
sampling height and climatic conditions in aerobiological
Peninsula over the last few years, as a consequence of
studies. J Invest Allergol Clin Inmunol 1999, 9: 253-261.
the new EU Common Agricultural Policy. In other
5. Muranaka M., Susuki S., Koizumi K., Takafuji S., Miyamoto
T., Ikemori R. Adjuvant activity of diesel exhaust particles
countries, a relationship between changes in crops and
for the production of IgE antibody in mice. J Allergy Clin
variation in pollen sensitization has been observed [18].
Immunol 1986, 77(4):616-623.
Some authors maintain that the effect of climatic change
6. Knox R.B., Suphioglu C., Taylor P., Desai R., Watson H.C.,
could cause an increase in the production of airborne
Peng J.L., Bursill L.A. Major grass pollen allergen Lol p 1
allergens, and therefore an increase in the severity of
binds to diesel exhaust particles: implications for asthma
symptoms and in the number of people becoming
and air pollution. Clin Exp Allergy 1997, 27: 246-251.
sensitized [19]. Another factor for the increasing
7. Cariñanos P., Alcázar P., Galán C., Domínguez E. Privet
pollen (Ligustrum sp.) as potential cause of pollinosis in the
sensitization to pollen in recent years might be the
city of Cordoba, south-west Spain. Allergy 2002, 57: 92-
worsening of pollution experienced in the city [8,20],
97.
mainly as a consequence of the rising number of diesel-
8. Cariñanos P., Sánchez-Mesa J.A., Prieto-Baena J.C., López
engined cars. Although the potency of allergenic extracts
A., Guerra F., Moreno C., Domínguez E., Galán C. Pollen
has probably increased in the last few years with
allergy related to the area of residence in the city of Córdoba,
increasingly purified extracts, there is a growing body
south-west Spain. J Environ Monit 2002, 4:734-738.
of evidence that points to a close association between
9. Domínguez E., Galán C., Guerra F., Villamandos F., Infante
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56
© 2005 Esmon Publicidad

---

Pollen allergy in Cordoba city
56
F., Mediavilla A. Spring pollen and related allergies in
part of the Iberian Peninsula. Clin Exp Allergy 2002,
southern Spain. J Invest Allergol Clin Immunol 1993, 3(5):
32(11):1606-1612.
271-275.
17. Bousquet J., Cour P., Guerin B., Michel F.B. Allergy in the
10. Domínguez E., Galán C., Villamandos F., Infante F. Manejo
Mediterranean Area. Pollen counts and pollinosis in
y Evaluación de los datos obtenidos en los muestreos
Montpelier. Clin Allergy 1984, 14:249-258.
aerobiológicos. Monografías REA/EAN 1992,1: 1-13.
18. Hopkins A., Davies R. Changing grassland utilization in the
11. Domínguez-Vilches E., Cariñanos P., Galán C., Guerra-
United Kingdom and its implications for pollen production
Pasadas F., Infante F., Villamandos F. Airborne pollen
and hay fever. Grana 1995, 33: 71-75.
concentrations, solid particle content in the air and allergy
19. Emberlin J. The effects of patterns in climate and pollen
symptoms in Cordoba (Spain). Aerobiologia 1995, 11:129-
abundance on allergy. Allergy 1994, 49:15-20.
135
20. Cariñanos P., Prieto J.C., Galan C., Domínguez E. Solid
12. González-Romano M.L., Candau P., González-Minero F.J.
suspended particles affecting the quality of air in urban
Pollen calendar of Seville and its relation to allergies. J Invest
environments. Bull Environ Contam Toxicol 2001, 67: 385-
Allergol Clin Immunol 1992, 2(6):323-328.
391.
13. D’Amato G., Liccardi G. Pollen related allergy in the
European Mediterranean area. Clin Exp Allergy 1994,
24:210-219
14. Lebowitz M.D., O´rourke K. The significance of air pollution
in aerobiology. Grana 1991, 30: 31-43.
Juan Antonio Sánchez Mesa
15. Alergológica: factores epidemiológicos clínicos y
socioeconómicos de las enfermedades alérgicas en España,
Department of Plant Biology, University of Córdoba, Colonia
1995. Sociedad Española de Alergología e Inmunología
San José, 4
Clínica y Alergia e Inmunología Abelló, S.A. Madrid.
Campus de Rabanales, E-14071 Córdoba, Spain
16. Sánchez Mesa J.A., Galan C., Martínez Heras J.A., Hervás
Telephone +34 957 218 719
C. The use of a neural network to forecast daily poaceae
Fax: +34 957 218 598
pollen concentration in a Mediterranean region: the southern
E-mail: bv2samej@uco.es
© 2005 Esmon Publicidad
J Invest Allergol Clin Immunol 2005; Vol. 15(1): 50-56

---