Cat spit mystery: Why am I allergic to one of our cats, but not the other?

September 8, 2008 6:58 PM

Cat spit mystery: Why am I allergic to one of our cats, but not the other?

We have two cats; Polly, a Russian blue girl, and Eddie, a stripy boy of unknown/mixed origin. I love them both, but for some very odd reason, I'm allergic to Eddie's spit. I know this because any time he licks me on the hand, say, or brushes his moist nose on exposed skin it immediately becomes itchy, and I get a raised, welty area. This subsides in an hour or so and isn't much of a drama, but what is interesting to me is the welt always looks exactly like the area his saliva or nose touched - say, for example, if you for some reason decided to trace a big X on my wrist with his nose, I would get a big, red, itchy X on my skin. If I'm in a confined space with Eddie, I launch into classic uncontrollable sneeze response, which I assume is linked to dander specific to Eddie.

I don't need a solution to this problem - it's not such a big deal, but I'm really interested to know why I would be allergic to one cat and not the other. Polly, being Russian Blue, is much fluffier, but I have no response to her saliva or fur whatsoever.

I'm curious - what's the deal with Eddie's spit? I thought from an allergy perspective a cat was a cat was a cat.

posted by lottie to pets & animals (12 comments total)

The wiki page for russian blues alleges that they might be hypoallergenic. I don't know how much stock I'd put in that, but it's quite possible that one breed is more irritating than the other.
posted by nursegracer at 7:39 PM on September 8, 2008

Anecdotally, allergic response definitely depends on the individual cat. I'm extremely allergic to the saliva and dander of some regular ol' domestic shorthairs, and hardly allergic at all to others. I don't know why, though.
posted by hippugeek at 7:47 PM on September 8, 2008

Oddly, I have a cat of somewhat Russian blue origin. My roommate (until recently) had a cat of the mixed/calico variety. I was viciously allergic to my roomie's cat. Can't explain the science to you really, but just know that you are not alone. I guess it's kind of specific in the way that you might be allergic to one perfume and not the other. Who knows.
posted by greta simone at 7:49 PM on September 8, 2008

So wierd that greta simone has experienced the same... innnntersting.
posted by lottie at 7:55 PM on September 8, 2008

I used to have a black moggie, possibly part Siamese or Burmese, who could raise hives on the inside of my forearms if she licked or nuzzled me there for a prolonged time. My tabby and my Burmese never caused hives no matter what.

But over the past year or so, the Burmese has started to cause me to sneeze and will occasionally raise hives on my forearms if he nuzzles me for a while. So there is the possibility that you're quite allergic to one cat right now, but may become more generally allergic to all cats as time passes.

For now, I keep Fergus' dander down with regular baths, which helps my sneezing, but there's not much I can do about my sensitivity to his spit except for minimizing my exposure to it. Teach Eddie how to use kleenex or something. And if you can, start bathing him weekly to cut down on the dander.
posted by maudlin at 8:07 PM on September 8, 2008

Anecdotal on the Russian Blue front: I know a woman who's very allergic (sneeze/welt, but not airway constricting) to most cats. She house-sat for someone with a Russian Blue and was ok, so got two Russian Blue cats of her own and doesn't have an allergic reaction with them. (I think she had a small reaction at first which settled down, and she does common sense anti-allergen things like having hardwood floors that she keeps clean etc.)
posted by LobsterMitten at 9:17 PM on September 8, 2008

Siberian cat science!
posted by hortense at 9:43 PM on September 8, 2008 [1 favorite]

I've a similar situation - I'm hideously allergic (Zyrtec everyday, hand washing any time I pet him) to my fine-coated silver tabby, and not at all to my plush brown tabby. Interestingly (to me), our new kitten happens to be an Oriental-type mixed thing who shares a lot of physical similarity to the silver tabby, and she provokes my allergies, too.

No idea why, so I can't really help, but I was so happy to not be alone, I had to speak up.
posted by batmonkey at 10:08 PM on September 8, 2008

Over 90% of individuals who are allergic to cats, are allergic to a single protein, Fel d 1, that is present in the cat's saliva* (though I can't find a reference for this statistic, it's what I've been taught).
*(and since cats lick themselves, the protein gets on their fur and that's why people react to cat hair).

Years ago, there were promises that some Biotech companies were going to create a hypoallergenic cat by knocking out the gene for Fel d 1. This would have been expensive and time consuming and AKAIK it hasn't been done. Instead, it has been claimed that Allerca discovered a cat breed with a naturally occurring mutation of this gene, and used it to breed their hypoallergenic cats.

Unfortunately, none of this is in the scientific literature, so it must be taken with a grain of salt. It is very possible, however, that Polly has a mutation in this gene. If you know other people who are allergic to cats, and they are not reactive to Polly, then the likelihood of this gene being responsible increases. You'll never really know for sure though.
posted by kisch mokusch at 2:05 AM on September 9, 2008

As well as the possibility of Eddie being exceptionally allergenic to people generally, it's possible you are more exceptionally allergic to him than people generally. It's also possible you are more allergic to male cats generally than female cats generally. If you really want to find out: hug friends' cats and record your reactions; have friends hug your cats and record their reactions. While this is technically animal experimentation, I think it will pass ethical muster.
posted by aeschenkarnos at 5:12 AM on September 9, 2008

Data point: I grew up with cats & have been around tons my whole life & have always been moderately allergic to them, but I have a tortie calico now that gives me the same reaction -- wherever her nose touches me, a raised itchy nose-shaped welt appears. No idea why, but you're not alone!
posted by oh really at 6:55 AM on September 9, 2008

Thanks everyone - I guess no real scientific data, but it's great to know that it's not all that uncommon. FWIW, I favour the idea proposed by kisch mokusch that a modified gene may be responsible. I think the big part of it is that it had never really occured to me that Polly may be less of an allergen, than Eddie having something about him which makes me itch. I'd always focussed on Eddie and assumed he had irritating spit - by this I mean I know think the reverse: I'm allergic to cats generally, but Polly has special qualities.
posted by lottie at 7:54 PM on September 10, 2008