Blood Suckers

Lately I’ve focused this column on consequences of all that time we’re spending outdoors. In the Pediatric Emergency Department we’ve seen lots of related injuries and skin problems.  Now let’s talk about wild beasts your kids might encounter, especially the deadliest animal known to man.  Causing the most fatalities world-wide every year, this animal kills far more people than sharks, snakes, hippos, crocodiles, lions, tigers, or bears.  Way more than murder hornets or killer bees.  This vicious scourge is that blood sucker, the mosquito.

The mosquito kills so many people by transmitting disease when it bites.  Fortunately for us in the United States, it’s bloated world-wide death toll is mostly from malaria, a tropical illness in Africa, Asia, and Latin America.  However, mosquitoes are beginning to spread other tropical diseases from the southern hemisphere to us, like Zika, Dengue fever, and Chikungunya.  Then there’s diseases that mosquitoes already carry locally, like Eastern Equine Encephalitis and West Nile virus.

Mosquitoes often hit and run before you know they’ve come.  They land, stab you with their needle-like nose, suck up blood while simultaneously injecting anticoagulant to prevent clotting in their nose, and lift off with a belly full of your blood, all within a minute.  Only after your body reacts to the anticoagulant, causing that ferocious itch, do you realize you’ve been a victim.

In my practice, that itch does the most damage to kids.  They scratch those bites with dirty fingernails and cause localized skin infections.  I see West Nile or other encephalitises maybe once every five years.  I see infected mosquito bites daily.

In spring I like a beer on my patio as the sun goes down, the temperature’s the nicest, and unfortunately when mosquitoes are most active.  I spray repellent on myself and clothes and put out citronella candles.  I also keep my grass mowed, because long grass hides water that mosquitoes like to breed in.  I also make sure there’s no standing water, like in gutters or buckets.  The one water feature in our yard, the birdbath, has a dripper fountain- mosquitoes don’t lay eggs in rippling water.  Do the same with your yard and your kids.  And keep those nails clean and clipped.

Another of nature’s blood suckers is a hitchhiker, grabbing onto unwitting passersby.  This vampire doesn’t have pale skin, slick hair, and pointy canines, or get rides with it’s thumb out (who’d pick up that guy anyway?).  This horror movie happens on a tinier scale: the tick.

To get out of the home, get some exercise, and get kids away from their electronic heroin, we’re heading outdoors to woods and parks.  In spring, ticks are also hitting these places, clinging to bushes and grasses that we walk past.  As we brush by, the tick latches on to our clothes with hooks on it’s legs.  It’s swooped up and crawls to a hidey hole on the skin.

Until recently, we didn’t know how ticks actually sucked blood.  It certainly wasn’t the lightning fast stab-and-run of the mosquito.  Ticks take hours before they get their “blood meal.”  Then, in 2013, German scientists filmed the event.  Dr. Dania Richter of the Technische Universitat of Braunschweig is a researcher on how ticks transmit Lyme disease to humans. One day, as I imagine it, her team was lounging around the lab when she said, “Hey Franz (the actual name of one of her collaborators), let’s film some ticks sucking blood!”  They got some high speed, high res cameras and mouse “volunteers,” and made bug research history.

Instead of the quick stab of the mosquito, it’s a time-consuming process for ticks. They first cut into your skin with two tiny saws at the front of their heads.  Then they stick a fat harpoon between the saws.  Alternating thrusts of the saws and harpoon, they claw their way deeper until blood flows back into the mouth.  See it on Youtube!

Ticks occasionally transmit diseases like Rocky Mountain Spotted Fever, Erhlichiosis, and Tularemia.  But mainly, they’re just gross.  Prevent bites just like with mosquitoes: spray repellent on your skin and clothes, wear long sleeves and pants (if you can stand the heat), and keep yard grass short.  After hiking, when you shower off the dirt and sweat, check all your skin for ticks.  If you see one, pull it off with tweezers by the head, as close into your skin as possible.  You don’t have to turn your skin into hamburger getting all those saws and harpoons out- they don’t transmit disease themselves.

 

 

Miniature Monster Movies

I loved japanese monster movies as a kid, watching titanic lizards and insects stomp scale models of Tokyo.  Doctors are biology nerds at heart, and find depictions of biology-gone-haywire entertaining.  So you’ll understand my thrill at an American Academy of Pediatrics conference where we learned why there’s few Lyme disease cases in Louisiana.

Lyme disease is transmitted by deer ticks.  Lyme bacteria is carried in deer and mice,  tick feeds on those, and then when biting humans, regurgitate the bacteria into the human.  Infection starts with a target-shaped rash at the bite site: a central red spot surrounded by a red ring.  If untreated Lyme can infect joints and even the brain.  So why don’t we see Lyme in the South?  It turns out that while ticks in the North feed on mice and deer, ticks in the South feed on…..LIZARDS!  COOL!  Talk about monster movies in miniature! 

While lizards have proteins in their blood that kill Lyme, humans have to worry about Lyme and other tick-borne infections.  Rocky Mountain Spotted Fever, Erlichiosis, and Tularemia are just a few of the tick-borne infections.  Now that it’s a warm and lovely spring and we want to be outdoors with blooming flowers and trees, ticks are blooming too.   

Ticks live in bushes, dead leaves, and tall grass, so hiking, hunting, camping, and gardening are perfect activities for ticks to hitch a ride as we brush past. To prevent this, wear clothing treated with 0.5% permethrin, or spray clothes yourself.  Ticks climb upwards, under pant cuffs, so tuck those cuffs into socks or boots to keep them off your skin.  You can put certain sprays on your skin, but some you can’t put on kids under 3 years-old, and none on babies under 2 months.

Soon after being outside, shower to not only wash off sweat and dirt, but wash off ticks. While doing so, inspect for ticks that have already started to burrow into skin.  Ticks love to hide- in hair, behind knees and ears, in armpits and belly buttons, under waist bands, and way up between legs.  Check those places carefully.

Let’s continue our theme of minature monster movies, starring ticks and lizards.  When we discussed ticks feeding on lizards and humans, what exactly does that mean?  Well, horror-movie fans, it means they suck your blood!  How they do that has been unknown, until 5 years ago when german scientists caught the act on film.  Go to Smithsonian.com to watch that mini-monster movie.

Ticks have two specialized harpoons on their heads called chelicerae (pronounced Kale-y-Siri).  These harpoons are covered with barbs like fish hooks, so as they plunge into your skin, the barbs lock in.  After about 30 thrusts of these weapons, the tick’s deep enough to deploy another barbed spear called the hypostome. This thrusts down between the chelicerae to open a big enough path for blood to flow up to it’s mouth.

About this time we discover the tick on our kid, head buried, body sticking out.  After experiencing a profound case of the creeps, it’s time to act. If the tick can’t be brushed off, it means those barbed spears are stuck in.  Your grandparents’ methods of removing ticks won’t work.  Smearing them with butter to suffocate them so they’ll run away- myth. Touching them with a hot match-head- kills them, but they don’t release.  Painting them with toxins like nail polish or gasoline- same result.  They die, but die before they can extricate themselves.

Tweezers are the best way to remove ticks.  Grasp the tick by its head, up against the skin, and pull gently but firmly.  If the tick breaks and the head’s still embedded, you can pick it out with a sewing needle and tweezers, like a splinter. The good news is that you don’t have to turn your kid into hamburger to extract every last fleck of tick parts. The chelicerae and hypostome don’t carry disease, and the skin will extrude those with time.

More good news. If you catch the tick before it’s engorged, it won’t have transmitted disease. Ticks only regurgitate infections after a blood meal.  They need to get full of blood before refluxing blood and infection from the rear of their bodies down into you. So if the tick isn’t swollen, it’s cool as far as worrying about Lyme disease or Rocky Mountain Spotted Fever.  The monster loses!