Hay fever season arriving early this year

© Hollandse Hoogte / Bert Beelen
In 2019, people suffering from hay fever have bought their pollen allergy medication relatively early in the year. The first peak in purchases of hay fever medication was already reached between February and early March, more than one month earlier than in previous years. Statistics Netherlands (CBS) reports this on the basis of new sales figures of hay fever medication, as reflected in the hay fever index.

CBS published the hay fever index for the first time in the spring of 2018. This index shows how the hay fever season progresses on the basis of pharmacy sales of hay fever medication. Last year, turnover of hay fever medication showed a higher peak than in previous years, partly because of the warm weather in April.

In the chart below, the turnover index shows the development of weekly sales of hay fever medication relative to the average weekly turnover in 2016. The same chart displays the changing count of allergenic pollen in the air. It also shows the pollen counts - measured by Elkerliek Hospital - of tree and plant varieties which trigger moderate, severe or very severe allergic reactions such as the hazelnut tree, alder, birch, Poaceae, Rumex, Plantago, Cedar of Lebanon, Artemisia and Ambrosia. Peaks in the sale of over-the-counter medication for the treatment of hay fever are found to coincide, more or less, with airborne pollen counts.

Turnover in hay fever medication and pollen concentrations in the air
   Turnover index medicationMost allergenic pollen
2016126.524
2016223.43
2016322.413
2016424.3107
2016527.51013
2016632.9269
2016730.0263
2016835.2179
2016934.9133
20161065.9276
20161195.3303
20161273.4199
20161392.442
201614134.71177
201615228.43475
201616179.9363
201617108.6282
201618326.3711
201619373.3231
201620182.9204
201621259.785
201622510.4506
201623561.1563
201624159.939
201625142.1167
201626113.00
201627135.2510
201628119.1195
201629123.0181
20163088.416
20163168.768
20163262.198
20163367.782
20163465.1105
20163557.273
20163654.5102
20163753.344
20163851.848
20163944.771
20164041.79
20164131.29
20164232.13
20164328.11
20164425.40
20164522.51
20164621.41
20164723.61
20164822.40
20164920.70
20165022.50
20165127.20
20165226.66
2017124.96
2017222.521
2017322.17
2017424.910
2017525.918
2017623.03
2017731.2351
2017840.4880
2017953.8150
20171065.347
201711111.3124
201712110.79
201713221.32623
201714184.81017
201715172.5381
201716120.8143
201717115.393
201718126.764
201719144.726
201720171.5171
201721420.1
201722505.9290
201723272.9307
201724297.9139
201725238.0235
201726126.0122
201727129.6156
201728103.781
201729109.325
20173083.364
20173173.950
20173262.663
20173356.965
20173464.662
20173556.026
20173644.37
20173736.025
20173837.731
20173933.917
20174030.520
20174130.56
20174230.11
20174330.61
20174430.21
20174527.40
20174624.90
20174725.70
20174825.50
20174921.93
20175032.90
20175142.92
20175242.448
2018129.15
2018227.270
2018325.923
2018431.8143
2018534.460
2018631.2143
2018733.1262
2018838.3217
2018933.584
20181058.91054
20181183.3237
20181266.742
20181378.58
201814126.1330
201815263.23709
201816540.14398
201817257.8380
201818231.045
201819293.788
201820204.9120
201821607.4661
201822452.5742
201823302.0318
201824203.2312
201825138.1189
201826168.9281
201827169.7236
201828110.2124
201829117.261
20183092.5145
20183175.096
20183257.6100
20183349.311
20183446.114
20183544.128
20183637.461
20183736.986
20183837.462
20183934.818
20184030.64
20184129.56
20184235.43
20184333.26
20184431.42
20184528.40
20184625.90
20184728.43
20184827.10
20184925.01
20185026.60
20185133.010
20185241.549
2019138.349
2019230.13
2019335.554
2019431.812
2019531.922
2019632.5157
20197100.44915
20198258.14242
20199279.91366
20191091.275
Source: CBS, Elkerliek hospital

High pollen concentrations in February

A sharp increase in concentrations of alder and hazelnut pollen in particular was measured in February, following a week with relatively high temperatures. This immediately led to increased sales of hay fever medication, which lasted for several weeks. Sales dropped again at the beginning of March, when pollen concentrations in the air had decreased significantly.

Turnover of hay fever medication

The hay fever index - the turnover index of hay fever medication - is based on weekly sales figures obtained from Dutch pharmacies. This involves self-medication products which are available without prescription at a pharmacy. This type of medication is in the form of tablets, nasal sprays or eye drops which relieve allergic reactions. These weekly data have been processed by the CBS Centre for Big Data Statistics (CBDS) into a weekly turnover index of hay fever medication. The turnover index is not designed to provide the total sales volume of hay fever medication in the Netherlands, but to give more insight into the development of the hay fever season and the purchasing moments of consumers, based on developments in weekly sales.

Sources