Nasty respiratory response to colleague's perfume. What can be done?

A friend of mine is having difficulties at work with multiple colleague's perfume/cologne/personal hygiene products. He's tried to deal with it with his direct supervisor with limited success. The company allowed him to use a different office away from the offending 'chemicals' temporarily, but that will probably change. The issue is that when exposed to whatever irritant, he closes up...breathing becomes difficult, throat burns, eyes water, etc. He's seen a doctor who advised him this is not an allergic reaction, but rather a 'respiratory irritant'. The doctor said an asthma-type inhaler won't work in this type of situation, and gave him some sort of steroidal inhaler that didn't have any effect. He's also tried to involve HR, but they advised him there's not much they can do other than moving him to another office. Today is the first time that his direct supervisor is wearing something that is irritating his respiratory system. After meeting with her for a few minutes, he had a very nasty reaction. He mentioned it to her, and she became very defensive saying things such as, "nothing's changed" or "I don't know what it is" etc. He then saw the health center in his work, and they dispatched him to the hospital. My question is, does he have any recourse here? He's saying his supervisor may hold it against him as she has done in the past with her other direct reports that have had medical issues. My thought is that this can't be right...a medical issue should be treated seriously. What can he do about this?