August 10, 2017

Heavy summer rains portend a potent fall allergy season – but start treatment now

The upcoming allergy season could bring a lot of sneezing, especially if we see a lot of hot, dry days in August and September on the heels of a lot of rain in July.

The Philadelphia region received 5.35 inches of rainfall last month – its highest amount since 2013 and the third-highest mark in the last decade, according to the National Weather Service.

That wetness, which has continued into early August, does not bode well for people who suffer from ragweed allergies.

The rainfall spurred the growth of ragweed plants, which blossom in late July and early August. A dry, hot August and September would allow their pollen to remain airborne, potentially causing a dreadful allergy season.

"If we get nice weather and not a lot of rain, expect that we will have a high ragweed season," said Dr. John V. Bosso, director of the Otorhinolaryngology Allergy Clinic at Penn.

Another 2.75 inches of rainfall fell in the region in August – a total that already doubles the rainfall of the last two Augusts. But June saw the lowest rainfall level of the last 10 years, at 1.86 inches.

The table below shows the Philadelphia region's rainfall totals, in inches, from the last 10 summers, according to the National Weather Service. This month's tally is through Aug. 9.

Year  JuneJuly  AugustTotal 
 20171.86 5.35 2.75 9.96 
2016 1.873.88 1.70 7.45 
2015 8.883.16 0.98 13.02 
2014 5.464.30 3.55 13.31 
 2013 10.5613.24 5.91 29.71 
 20122.94 1.48 5.37 9.79 
 20112.56 2.71 19.31 24.58 
 20102.05 6.28 2.19 10.52 
 20094.79 3.35 10.29 18.43 
 20082.87 3.45 2.44 8.76 

Overall, the summer's total rainfall appears destined to land near the middle of the totals from the last decade, save a tropical storm.

Still, July provided the preseasonal wetness that can lead to a bad allergy season, Bosso said.

"By the end of July, it's pretty much ready to rumble and ready to go," Bosso said. "By early August, we're able to measure significant amounts of (ragweed pollen.)"

Currently, ragweed pollen is present but very low, according to The Asthma Center, the region's official pollen counter. But it expects the pollen to "flood" the region throughout the next several weeks.

Ragweed pollen causes allergic symptoms ranging from sneezing to clogged sinuses to asthma and ear infections.

People who are allergic should consult with their allergist or physician to determine a plan of action, Bosso said. He advised the allergic to avoid the outdoors during the middle of the day, when the pollen count is highest, and use air conditioners, which capture the pollen in their filters.

For people who prefer fresh air, special window screens can prevent pollen from entering a home.

People also can take allergy medicine or use steroid nasal sprays – but their maximum effect takes days to achieve.

"They should have been started already, because we're already in the season," Bosso said. "The earlier someone starts, the more likely they are to be effective."

For people with more extreme symptoms, immunotherapy injections are available. But they also need to be started before the season arrives to achieve their fullest effect.