There's some kind of allergies going around these days that are caused by the temperature going up and down all the time in Japan.
この場合、次のような言い方ができますよ。
ーThere's some kind of allergies going around these days that are caused by the temperature going up and down all the time in Japan.
「日本では最近寒暖差によって起こるなんらかのアレルギーが流行っている」
to go around「流行る」
temperature going up and down「気温が上がったり下がったりする」
ご参考まで!