Can mere exposure to sunlight trigger an asthma attack?

Factual Questions
1

I know someone who has been an asthmatic since childhood. As an adult, he says that being exposed to intense enough sunlight can cause what he feels to be the beginning of an asthma attack.

I have personally witnessed him ski, with no adverse effects. I imagine the sun rays weren’t particularly direct at that time.

He also works out at gyms, but I think he does mostly weights and not a whole lot of cardio activity.

Being indoors when it’s very hot also does not trigger his asthma.

So is this possible? Is there some other explanation?

2

Maybe he’s got some version of the photic sneeze reflex, and interprets it as the beginning of an asthma attack? Cecil on photic sneezing:
Why do some people sneeze when going out into bright light?

3

He doesn’t sneeze, and I think it’s more of a tightness in the chest, but thanks for the reply. That column has some interesting info and may be pertinent in any case.