Mosquito Magic Uncovered!
June 19, 2008 9:00 AM   Subscribe

Is it possible for a person to have natural immunity to bug bites? I haven't had a single bug bite in over 15 years and am starting to think I'm a medical anomaly!

I remember getting bug bites as a child, but I can't seem to remember getting a single bite since I hit puberty around 12-13 years old. I thought it might be related to the flora and fauna of the areas in which I have lived (PA, WV, and DC). However, I recently went on vacation and got confirmation of my weird immunity!

I was in Mexico for 5 days with 3 of my friends. The humidity was especially high one evening, and all 3 of my friends got TORE UP by the mosquitoes. When they woke up the next morning, they each counted at least 30 or more bites on their feet, ankles, and arms. The bites were angry red welts that itched and burned.

On the other hand, I didn't have a single mark on me. Not one. No welts. No itching. No burning. I had not put on any insect repellant that evening and was also wearing perfume.

How is this possible? Is there some kind of medical explanation for why I don't seem to attract insect attention? Does anyone else experience this? Mind you, I am not complaining about this lack of love from bugs. I'm perfectly happy with them keeping their distance.

If it matters, I am a 30 year old, Caucasian female.
posted by clpage to Health & Fitness (24 answers total) 3 users marked this as a favorite
This is absolutely totally folk wisdom and I do not claim knowledge of the science behind it, but I have heard that having plenty of iron in your blood will drive the mosquitoes away. Maybe you get more iron than average?

I used to get eaten alive by mosquitoes every summer until my father told me about the iron thing. I started taking iron supplements the next year starting in May, and got only three bites or so all summer.

I've heard other various rumors about what mosquitoes do and don't like (like, they really like people who eat bananas??) but, again, I don't really know for sure.
posted by Metroid Baby at 9:12 AM on June 19, 2008

This is simpler than it sounds - some people don't mount an immune response to mosquito saliva. Varies with the type of mosquito too.
posted by ikkyu2 at 9:13 AM on June 19, 2008

This might be one possible answer
posted by le morte de bea arthur at 9:14 AM on June 19, 2008

Most people are allergic to insect bites, but some people aren't. You may well be 'immune,' in that you lack an allergy nearly everyone else has.

posted by Tomorrowful at 9:14 AM on June 19, 2008

I am by no means an expert, but when I was a child I was covered in mosquito bites in the summer. Now I never see a mark and haven't for years. I've been told that mosquitoes don't single anyone out, but some people are allergic to their bites, and that's what causes the swelling. Since allergies can sometimes resolve themselves, you've probably just outgrown it.
posted by Evangeline at 9:16 AM on June 19, 2008

The point about immune response is very interesting -- didn't know that. I was going to say that within our family, some of us are bitten quite a bit more than others, to the point where you can see more activity. My guess had been that some of us just smell different to them.

To your knowledge, is it that you're not being bitten at all, or rather that you're not suffering from the bites you get?
posted by Clyde Mnestra at 9:17 AM on June 19, 2008

I don't react to mosquitoes either, although I've been bitten by other kinds of bugs (spiders and stuff) and had a reaction.
posted by restless_nomad at 9:21 AM on June 19, 2008

Just to second ikkyu2, you can definitely develop an immune response. When I first arrived on my little island my reactions were pretty bad, but now, nothing-- I don't even have to bother with Off Spray. Some people tend to take much long longer to adapt, but most people would seem to get there eventually.
Also, mozzies do seem to like new blood better, I can be sitting on the boat and be free and clear, but a new recruit to the island might be a group meal. Maybe once your immune response kicks in something subtlety changes which makes you less desirable.
B12 complex is meant to minutely change the content of your breath (Mozzy's are attracted by your CO2 output) either via supplements or through the food you eat.
posted by Static Vagabond at 9:26 AM on June 19, 2008

My grandmother was "immune" to mosquitoes as well. My understanding (seems the same as ikkyu2) is that the itchy red welt is caused by the body's immune response and almost allergice reaction to mosquito saliva.

I rarely notice when a mosquito is actually siphoning off my blood unless there are hordes of them and I can actually feel their wings beating around me. I only infer later based on the angry red welt that I was bitten by a mosquito. Suppose I was bitten by a mosquito but my body did not mount an immune response (which involves histamine I believe) then I would not have the after-bite reaction (i.e. a red welt) and it would be reasonable to believe I had not been bitten.

After a long period without mosquito bites (which is actually a long period without mosquito bite immune reaction) I might believe I was immune to mosquitos.

Speaking on behalf of the non-immune: you're lucky but you'll get yours. :)
posted by KevCed at 9:28 AM on June 19, 2008

Response by poster: To your knowledge, is it that you're not being bitten at all, or rather that you're not suffering from the bites you get?

Up until my trip to Mexico, I would have said that I am not being bitten at all. During the night of the "great attack" while on vacation, I could have sworn that I felt some small pinches down around my feet. When I went looking though, there were no marks left at all.
posted by clpage at 9:32 AM on June 19, 2008

I have had a couple of bites in the last 20 years, but literally only one or two - often during periods when my wife has been eaten alive. I've had significant exposure to both mosquitos and fleas, and apparently neither much like to eat me.
posted by bifter at 9:39 AM on June 19, 2008

Body temperature plays a role as well, at least for 'skeeters. Even a very slightly lower normal body temp (like 98.4 instead of 98.6) will apparently send the nasty bugs in preference to warmer prey. I have a slightly lower than average body temp and I am NEVER bothered by mosquitos unless I'm the only edible thing around (or theres just hordes of them and they're not being too discriminatory).
posted by elendil71 at 10:08 AM on June 19, 2008

When I lived in Thailand, I never got bitten. Now, in the States, when the skeeters are biting I get bit along with everybody else. Don't know whether the difference is in me or the skeeters, but I thought I'd add a data point.
posted by languagehat at 10:28 AM on June 19, 2008

Best answer: Also, mozzies do seem to like new blood better, I can be sitting on the boat and be free and clear, but a new recruit to the island might be a group meal. Maybe once your immune response kicks in something subtlety changes which makes you less desirable.

This strikes me as very likely to be true.

The usual ingredients in mosquito saliva which provoke an immune response are anticoagulants; after you have been bitten many times, you may well develop a level of circulating antibodies to the anticoagulants sufficient to bind to almost all of them the mosquito injects into you very quickly (which I think is at the root of a failure to develop an itchy welt), neutralizing them and interfering with its ability to get a proper meal, and probably more importantly, to digest the meal before it coagulates in the mosquito's gut.

However, that would seem to require that mosquitoes are able to detect at a distance something about a person who is immune to them, and it's hard to imagine what that might be (but intriguing; if it exists, maybe we could imitate it).

I've wondered what advantage mosquitoes get from allowing malaria parasites to hang around in their salivary glands; maybe the presence of the parasite prevents or delays the development of immunity to the anti-coagulants, by giving the immune system something more significant to react to.
posted by jamjam at 10:51 AM on June 19, 2008

I live in the south, where mosquitoes are vicious, but I only notice a bite every year or two, I think it is because I tend to surround myself with people that get bitten all the time, so the little bastards are distracted by the more tasty targets.

If its the allergy thing, it would be funny, because I am allergic to everything else.
posted by yeahyeahyeahwhoo at 12:13 PM on June 19, 2008

Do you by any chance take antibiotics for acne? If so, they act as an anti-inflammatory, and at least in my case, made me basically immune to mosquito bites. Unfortunately, my super-power wore off once I stopped with the meds.
posted by spilon at 12:39 PM on June 19, 2008

I know I get bitten because I have watched a mosquito land, insert it's thingy and stay there long enough for it to drink and then fly off. But I have no reaction. So I am with the camp that says there is some kind of immunity rather than they do not like our smell.

I used to get a reaction as a kid tho. Also my body temp is usually lower but like I said, they land and drink, I just don't have any reaction.
posted by shaarog at 12:50 PM on June 19, 2008

Since skeeters are primarily attracted first by the CO2 in our breath and then by body heat, I find it unlikely that any personal chemistry wards them off. I used to get pretty normal bug bites that would itch for 24+ hours: I have become steadily and markedly less responsive to bites over the years, to the point that I now get the mildest reaction (slightest redness and raised area that I won't even notice if don't happen to catch the biter in the act, and vanish within an hour. So, you can definitely be immune and it can develop over time.

There may be something to the developed immunity theory jamjam proposes: I think I noticed a singular, marked reduction in my reaction after a particular incident involving watching a dance performance. Where a large crowd gathered around a lake in Minnesota. During the summer. At dusk. With giant spotlights ranged around the perimeter. (Thanks MacArthur Genius Grant recipients!) I got bit about a million times, primarily on my hands which were most exposed. I expected them to be swollen up like Mickey Mouse gloves the next day but when I woke up in the morning there weren't even any bumps. I might have just not been noticing the diminished reaction before that, though.

My sister, on the other hand, gets welts the size of a silver dollar, doesn't matter whether she scratches them or not.
posted by nanojath at 1:30 PM on June 19, 2008

It's OK, I'm alergic enough to bug bites for the both of us!
posted by meta_eli at 1:51 PM on June 19, 2008

I have an aunt who is immune from mozzies. She gets bitten, but doesn't notice and has no reaction.
posted by pompomtom at 4:31 PM on June 19, 2008

This is an interesting thread. I've always thought mosquitos east of the Mississippi didn't like me, but maybe my immune system just doesn't recognize them.
posted by small_ruminant at 10:17 PM on June 19, 2008

Yes, I'm immune, too.
I guess I'm just bitter.
posted by Methylviolet at 11:46 PM on June 19, 2008

I hate you. I hate you so bad.

Not only am I *always* the one that gets bitten up, I'm *seriously* allergic to them... the bites swelling to 2-3 inches across, sometimes. -sigh-

There are supposedly things that you can do to reduce attraction, such as not eat bananas and not be pregnant. Also, since I've been on an iron supplement I haven't had that much trouble from them.

Are you on a special diet, like vegan or something?

I don't really hate you. :)
posted by GardenGal at 8:47 AM on June 20, 2008

Me, no. I've always been immune, since I was a kid. And I'm sitting there watching my own poor children get devoured, while the airspace surrounding my body is mosquito-free. They are sweet, I'm bitter, that's why -- is the the accepted wisdom in my house. But really it is a mystery.
posted by Methylviolet at 8:50 PM on June 20, 2008

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