Anecdotal, but similar situation here for me (I don't need an inhaler, but visiting London around 2015 meant blowing my nose to black snot for a week, and then

Anecdotal, but similar situation here for me (I don't need an inhaler, but visiting London around 2015 meant blowing my nose to black snot for a week, and then back in 2024 it was completely fine)!