30 May 2012

Why mosquitoes love me and why I hate them

I was telling this story to some family members the other day and it turned out to be a bit funnier than it seemed when it was actually happening to me. It involves a little bit of science. You might want to get a cup of tea before you sit down to read it, because once I got going it was quite hard to stop...
 
Anyone who has been on holiday with me in recent years will have had to endure my nightly rituals. These begin around 5pm, after which time, room mates are not permitted to leave the apartment - or so much as open a door - until said rituals have been completed. I begin by dousing my entire body in something called ethyl butylacetylaminopropionate; this part can be lengthy, since I often forget whether I've attended to my right foot or my left elbow and then have to start over again just to be on the safe side. The chemicals dealt with, I carefully dress, being sure to cover every square inch of bare skin - including ankles, neck, chin, ears and forehead. If I can pull off a look that exposes only the parts of my face essential for breathing, that's ideal. Before reaching the door, I'll probably go back two or three times to top up on ethyl butylacetylaminopropionate, pop the rest of the bottle in my handbag and perhaps add a pair of sunglasses - by this time it's dark, but they're for covering the skin around the eyes rather than blocking out the sun. Being able to eat and drink - and to some extent see - in all this get up is desirable but not essential.
 
Really, it's all a small price to pay to keep out the little bleeders. The mosquitoes.

Until my late teens, I don't recall crossing paths with any of these unsavoury characters. For more than a decade, family holidays had alternated between a pleasant but ultimately dull stretch of coastline belonging to Cornwall and a pleasant but ultimately dull stretch of coastline belonging to one of the Channel Islands. Neither were home to swarms of mosquitoes. So it wasn't until about a week into a month-long InterRailing trip around Europe, during the summer holidays at university, that I felt I had really become acquainted with them. I was staying in (crummy) bed and breakfasts, or camping. One morning I woke up - at 6.30am, in just my underwear, as you do in a tent in Italy in the middle of July - to find my legs covered in angry red welts. About twenty or thirty of them. As the poison those pointy-nosed bastards had apparently poured into my blood worked its way through my veins, I began to feel increasingly weak and nauseous. The bites on my legs quickly turned to scabs as I scratched them raw, and those scabs eventually turned to scars that took years to heal. My tent mate had, highly improbably, I thought at the time, escaped with a few cursory bites - as if the swarm had given him a gentle nibble just to make sure and then decided I was much tastier.

In retrospect, it doesn't seem improbable at all. I've come to realise that given the choice of me or pretty much anyone I happen to be sitting or sleeping near, mosquitoes will always, without hesitation or deviation, choose me. I don't know exactly what it is about my flesh, or blood, that attracts them. Certainly, mosquitoes are known to display preferences for some people over others. Sensible, scientific publications suggest differences in warmth, moisture, chemical odours and carbon dioxide emissions (so... breathing?) influence their tiny, evil little brains. Slightly less reliable sources suggest eating certain potent-smelling foods to try to throw them off the scent - like garlic. Since I was in Italy scoffing pizza every night when the first attack happened, I don't really buy the garlic trick. A friend once said she attracted the bugs more than her sister because she smelled like jam. I'm not sure if this was because she ate a lot of jam... but these sisters were, incidentally, identical twins, which is interesting because genetic factors could be heavily involved in determining a person's attractiveness to mozzies. Thus, had the two of them eaten the same diet for a few weeks, perhaps their attractiveness would have evened out. Although I'm not sure the jam thesis would hold up under scientific scrutiny.

I digress. None of this quite explains how my mosquito aversion has reached the level of obsession that it has. The turning point was not the InterRailing trip. It was during a "relaxing" holiday with The Girls in Pisa in 2007. The month was October, which, according to the locals, was just the kind of time in the season the really vicious bugs would be about - the hardy ones that could survive all the way to the end of the summer and into autumn, and still come up biting. And it didn't take me long to find out just how vicious they were. On the very first night, I let my guard down. Oblivious to this new breed of October Demon Mosquito, I sat whoosily sipping wine and chatting until past midnight at the outdoor table in front of our holiday home. At some point, one of my friends leaned over and brushed a mozzie away from my face. I just smiled, thanked her and didn't think any more of it.

In the morning, I woke up and discovered, to great alarm, that I couldn't see properly - my left eye didn't seem to be working. Stumbling over to the mirror, I recoiled in horror upon finding that I had been punched in the face, with apparently ugly results. This was puzzling, since, despite the slightly slurry nature of the night that had just passed, I didn't remember at any point being punched in the face. After some tentative prodding around the puffy left eye, I was relieved to find that it did in fact still work. It had just been shut. And then I remembered the bug that my friend had swatted from my face. Damn mozzies, I fumed. Pisa mozzies must be super-mozzies. Getting as close as I could to the mirror, I found I could make out the spot where the bug had bitten me - a pinprick-sized puncture in the skin just below my eyelashes.

I moped about in sunglasses all day cursing the misfortune of looking like I'd been beaten up on my holiday. But the next morning, things got worse. When I woke up, the eye was closed again. As I turned over to get up and inspect it, I was aware of an odd sensation of movement across the top of my cheek and eyelid. What had happened was this: overnight, the eye had become extremely inflamed, presumably because my immune system had clocked it and completely freaked out. "WHAT is THAT?" it must have thought, and then sent its special forces division in to deal with it. The special forces division had obviously swum in, bringing with it a lot of fluid, because as I turned over - having slept all night on the side I'd been bitten on - this fluid began draining from one side to the other. There was so much of it that I could actually feel it moving across my face. Ee-uhw.

I was afraid to look in the mirror, but at the same time, unable to stop myself.

The eye had disappeared under the overblown bite. It was like something out of a horror movie, I swear. I was half convinced a mutant mosquito had crept under my skin and laid a clutch of eggs, which were about to hatch into giant slimy bugs and force their way out through my eye socket before eating me alive... Well, I was half convinced anyway. The other half of me reacted in the same way as it did when my appendix burst a couple of years ago. It pretended nothing was happening and that it was all going to be fine in the morning.
 
Luckily, one of my holiday buddies had some sense and marched me straight off to a chemist. So. I walked into the chemist in the centre of Pisa with my sunglasses on. The man behind the counter didn't speak very good English, so I don't think he really understood what I was saying, but he realised it was something to do with my eye and motioned for me to remove my sunglasses. Since I didn't speak any Italian, there was no way to warn him, so I tried to take them off slowly in case of frightening him. This clearly didn't work, because his reaction was that of a man who had just stepped on a rattlesnake. Or realised that the lady standing in front of him was about to hatch a brood of GIANT SLIMY MUTANT DEMON MOSQUITOES from her eye. He was most likely worried about being eaten alive because he didn't say much else and pointed fervently in the direction of the health centre.
 
This being Italy, the normal rules for getting a doctor's appointment didn't apply. The system in the health centre was difficult to decipher, but seemed to revolve around a man standing in a glass box. This part I only remember hazily... probably due to the psychological distress caused by the thought of the mother mosquito making her way to my brain... but it could have been one of the occasions in Italy where guns were on display. There always seem to be occasions in Italy where guns are on display. In any case, I got the general idea, which was to convince the man in the glass box of being genuinely ill. If satisfied, he would make you fill in a form and then sit or stand for hours in a sweaty room where it was impossible to breathe. Being foreign, I had to present some form of identification and - having left my passport in my room - tried to make him accept my student ID (I was doing a part-time master's degree). At this point, I still hadn't unveiled the mutant mosquito brood. Then I did the whole taking-off-my-glasses thing again and he didn't seem too bothered about the identification after all. By now, I was anticipating the response my eye was getting with a sort of morbid enjoyment, whilst simultaneously feeling certain that I was going to die. I briefly considered calling my parents to inform them of the fact that I was going to die, but decided it would be too expensive to call the UK on a mobile.

Right. So. I've got my form and my sunglasses are safely back in position. I'm walking down the street towards the hospital because that's where I've been told to go. The hospital in Pisa, it turns out, is a vast empty building with millions of rooms and a chronic shortage of signs. Maybe everybody in Pisa is really healthy, I thought, or maybe this was the special hospital for people whose bodies had been taken over by mutants and aliens. Or maybe everyone had already died. Whatever, there was a eerie feeling about this building and all its silent corridors. After some searching, I found a room with a couple of people in it, who turned out - suspiciously - to be just the doctors I had been looking for. Still, they seemed to understand the words "mosquito" and "eye", and weren't as perturbed as the chemist or the man in the glass box when I performed my sunglasses trick. While they examined my bloated eye, I imagined all the ways they might try to explain to me that I was going to die. Their English was limited, so I had to be prepared for them to be blunt: "Missus. Your eye..." [pointing, looking sad] "Dead."
 
Incredibly, I was allowed to leave the hospital with a prescription and BOTH of my eyes! I had of course believed that if I was to be brought back from the brink of death, it would certainly be at the expense of my left eye. But I and the eye had been mercifully saved! Hooray and other less polite exclamations! (And as a bonus, the complexities of the Italian health service as they applied to foreigners appeared to be such that the doctors decided to bypass them entirely and let me have my prescription for free).
 
To cut an even longer story to a slightly more reasonable length, I spent the next week carefully rubbing a steroid gel into the slowly deflating area around my eye, at four-hour intervals. Apparently, it wasn't possible to give me a regular cream because the skin under the eye is too sensitive. I'm still sceptical about that gel, since its effects were almost impercetible and likely the same as if I had left my immune system to its own devices. After about five or six days, the special forces division must have realised nothing was going on and vacated the area. But I spent the rest of my holiday in dark glasses or swimming goggles - carefully keeping my head above the water at all times to avoid washing off the gel. And if you look through my holiday snaps from Pisa 2007, you'll find several curious photos taken in the dark, in which I appear to have overdone the Audrey Hepburn-style head scarf with shades look. The rituals had begun.

So that's what happens if a mosquito bites you on the eye? Actually, it's what happens to me if a mosquito bites me on the eye; most people wouldn't react like I did. A couple of years later, I was in Ontario, Canada, staying in a cottage near the lakes - also, apparently, rampant breeding grounds for mosquitoes - when I got bitten on my arm. The bite swelled up to the size of a small but uncommonly itchy orange. I took a strong antihistamine pill and rubbed in lashings of calamine, which I later discovered is considered virtually redundant in modern medicine. Neither had much effect. The rest of the holiday was spent in itch avoidance.

No one really seems to know what proportion of people react like this when they get a mosquito bite. But since Canada, I've uncovered a few studies on so-called "Skeeter" syndrome in young children (including this one, which includes a photograph of a child with a surprisingly similar bite to mine, just below the right eye), and some references to an allergy test. It appears you can be allergic to mosquito saliva just like you can be allergic to pollen or a wasp sting. This means that, like in hayfever, your body overreacts to what it perceives to be an  invader, which is actually a harmless pollen grain or a drop of insect saliva. Despite the ugly results, I've only got a moderately troubling mosquito allergy. There are some people who will go into anaphylactic shock if they get bitten by a mosquito and have to carry around adrenaline injections. Until recently, I thought this only happened with bees or wasps. Not so.

After getting married last year, I worked hard at eliminating every last bug from our Sardinian honeymoon retreat - locking the door as soon as the sun went down and smashing their bodies against whitewashed walls. I did get a few bites and reacted worse than my new husband did to his, but not as badly I had in Pisa or Canada. It seems likely I've been bitten by different species of mosquito on different holidays, so maybe I just need to work out which species I'm allergic to, learn how to spot them at fifty paces, and then avoid like the plague... Or. I could try to naturally desensitise myself to mosquito saliva - this apparently happens over time, with people who have lived in Canada for longer reacting less severely to bites. My husband is half Canadian, so there's my ticket. Time to ditch the ceremonials; I just have to apply for Canadian citizenship, emigrate, and spend the entire mosquito season up at the lakes every year, getting the s*** bitten out of me. 

Sorry, mum, about my language in this post. And for some more serious science, here's an interesting study on mosquito allergies, which looks at the species of mosquito and immunology associated with severe reactions to bites. The authors mention that there are some rare reports of cross-reaction with allergens from insects in the group Hymenoptera. This means that in some people the antibodies that cause a reaction to mosquito saliva might actually be the same ones that cause a reaction to bee and wasp stings.