When Chigger Bites Escalate from Nuisance to Dangerous

Chiggers live in the grass and they bite you in the ass. Invisible mites, arachnids, nuisance to many, medically dangerous to some, ignored by quite a few…I could really do quite well without them.

They really will bite you in the butt. I’ve had bites on my right foot, on the shins where the tops of my socks hit, around the waistband of my jeans, on both buttocks, in the groin, on my right testicle, back of the upper arms, in and/or near the armpit, you name it.

I’d read of chiggers but had not encountered them prior to July of 2010. Red lice, head lice, revenooers too–wait, now I’m mixing up parasitic critters with the old White Lightning hit song which, come to think of it, was also about parasitic critters, albeit the governmental taxation sort of parasites.

[*Bonks self upside head to get things working again.*]

Okay. I’m back.

My wife and I moved to southern Cochise County, Arizona, in April of 2009. She’d lived in this county before, but it was my first go at residing in the desert, one mile north of the Mexican border. I’d not realized chiggers lived this far west. Aren’t those things all east of the Mississippi?

Oh, they’re here, all right!

As it turned out, the monsoon rains didn’t hit this area all that hard in ’09. Locals (including Pam) called it a “nonsoon” year. There wasn’t all that much explosive growth in vegetation, which meant it was pretty easy to stay in the clear, away from tall grass that hides fun things like Mojave green rattlesnakes, sizeable centipedes (5″ being most common here), scorpions, and yes, chiggers.

2010 was different. Chigger bites dotted my body by the time the summer wet season was over. They were irritating, itchy, but no more than that. Located off grid and having a long way to go to upgrade our living conditions, it wasn’t practical to scrub down in a shower every day or to take daily Epsom salt baths, which a friend who lives in Georgia remembered having to do as a child. I wasn’t really happy with the bites but didn’t find them to be too much of a problem.

Frankly, I’d just scrape the “crud” off with a fingernail–that being the feeding hole the chigger had made through the skin, a bit of buildup from reaction to the mild venom they carry, and most likely the invisible chigger itself. After that, it was simply a matter of hitting the bite site every once in a while with spray antiseptic and waiting it out. Each bite would itch noticeably for a week or so, sometimes taking as long a a month to disappear completely, but that was it.

Until this year, 2013. I’ve learned about preventative measures. We have a pressurized water supply now, a clawfoot bathtub with shower, all the amenities. On the days when exposure to “chigger grass” was unavoidable, such as when running the weed whacker, I made sure to bathe thoroughly after the work shift was done. Stepping in (or even on) any kind of vegetation was avoided as much as possible. When a brief exposure occurred, perhaps brushing by a single clump of grass or pulling a weed by hand, I brushed everything off (with my hands) as vigorously as possible immediately after contact.

These precautions worked…for a while. Chiggers are easy to brush off when they first arrive on your clothing or skin, even if you can’t see them. They’re also easy to wash off, at least most of the time. They don’t bite immediately. Instead, they start hunting for the perfect spot to go digging for gold–which, for them, is a batch of your liquefied skin cells.


Well, it’s like this, at least according to those who claim to know: Chiggers eat skin, but in phases. In phase one, their itty bitty short mouth parts take a chomp out of your surface skin…and then they spit in the hole. Or something like that. The spit starts dissolving skin cells whether you like it or not–or are even aware of it, for that matter. When the skin-spit combo gets to be a nice, goopy soup, the chigger slurps it up, high powered nutrition through a straw made by dissolving a piece of you.


When you scratch a bite site, the chigger larva is usually dislodged, falls off, and soon dies. I like that part. You bite me, redbug, you die! (They apparently call chiggers redbugs in the southeastern states.)

Admittedly, the baby chigger you just murdered does get its revenge. The goopy slurp left behind, having been scratched, is now exposed to air and hardens into a nice, irritating, crusty cap…which begs to be scratched all over again. Secondary infections from the scratching are common. Itching never quits quickly; it always hangs on for at least five days and often a lot longer.

In the end, I managed to avoid getting bitten this year until August 15, a new record for me (excluding the nonsoon year of 2009).

Unfortunately, the chiggers made up for that late start with a vengeance. I seem to be developing a serious allergy, or at least a major sensitivity, to the little bugs with their multiple legs and their nasty little biting mouth parts.

What had in earlier years been an irritating but minor nuisance…had developed into a significant medical problem, a potentially dangerous situation.

No bite from earlier years had flared into the sort of inflammation seen in the photo below. This picture was taken minutes ago, by flashlight, of my latest bite. It’s located on the inner left thigh. It itches, it burns, it does not make me love chiggers a whole lot.

Chigger bite on a 70 year old Caucasian male's left inner thigh, Cochise County, Arizona, September 24, 2013.

Chigger bite on a 70 year old Caucasian male’s left inner thigh, Cochise County, Arizona, September 24, 2013.

Allergies have not been a problem for me…until now. A big ol’ bald hornet came flying straight at me from across the Clark Fork River in Missoula, Montana, when I was eight years old. I watched it come, fascinated, never dreaming it was going to slam into me right between the eyes at full throttle, stinger first, leaving a clearly visible hole while producing no swelling, no inflammation whatsoever.

Mosquito bites, bee stings, no problem.

Perhaps I’ve changed. Who knows?

Remarkably enough, chiggers do not bother every human. Neither my stepson (Zach) nor our friend and neighbor (Robert) have any problem whatsoever with the little buggers, and these two men have lived right here in Cochise County from the days they were born.

Nor do they bother people who live in most of the states where I lived the first 65 years of my life, which is why I’d not encountered them until moving to the southwest.

Beyond that, they’re only active when the humidity is relatively high. There appears to be a magic cutoff point: I rarely get a chigger bite when the humidity is below 45 percent. (I say “rarely” because I did once hike through winter dead grass in January with the humidity down in the 30’s…and got a bite. But only once.)

In the southeast, that most likely means they’re active year around. In Cochise County, though, we “only” have a few months of each year to worry about. Once the monsoons hit, usually in late June or early July, the humidity jumps up into the Chigger Zone and stays there for some time after the rains have tapered off to pretty much nothing in September. The air doesn’t dry out all that quickly; today (September 24) our little weather station is showing the humidity at 51%.

Still very much in the Chigger Zone.

We have a lot of grass and weeds that need to be whacked. Except for the essential pathways, though, the vegetation will be left alone until somewhere around early November. The grass will be dry then, with few if any chiggers chomping.

Fortunately, the Internet has some great (i.e. easy to understand) articles on how chiggers work. One of the best (in my opinion) is by The Dragonfly Woman. Her complete article is well worth reading. Here’s a teaser.

Chiggers don’t just eat the top layer of skin cells though – they go for the good stuff underneath. To do this, they pierce the skin with their chelicerae, then inject saliva to digest the tissue and expand the wound. The goop that is produced is slurped up by the chigger. Remarkably, they also inject compounds into the wound that cause an immune response in the host animal, one that hardens the tissue around the bite site. In essence, the hardened tube-shaped structure that forms (called a stylostome) is a straw that expands deeper and deeper into the host. The chigger injects more saliva and sucks up more liquified tissue as the stylostome gets longer and longer. That’s right! Chiggers have tiny mouthparts, but they use their host’s own immune system to enlarge their mouthparts into a stylet like those of mosquitoes or a beak like those found in the true bugs! Now if that isn’t amazing, I’m not sure what is.

According to my research, it’s the larval stage of the chigger (six legs) that does the biting. The later nymph and adult stages have eight legs and do not bite.

Thus, the six legged biter, though too small to see without a microscope, looks like an insect–a tick or some such. But it’s not. It’s a really, really mean baby arachnid. So there.

Some online sources of chigger information are about as disturbing as the chiggers themselves. Example: One “chigger distribution map” brings up far more questions than answers.

–Why does it show Arizona “clear” of chiggers (white) when we know we’ve got plenty of them every summer?

–Are chiggers really active that far north? North Dakota, for cry-yi? Is no place safe?

–Is California truly clear of the little monsters? After all, California has everything else; how could it not have chiggers?

–Did the maker of this map know what he (or she) was talking about?


There seems to be a consensus that it’s the scratching (and subsequent minor infection) that generally causes the most inflammation in severe situations. I’m not sure that’s right, but I do know one bite about a month ago had some pretty serious consequences. The bite was situated on the back of my upper right arm. As the days went by, the inflammation spread all the way down to envelope the entire elbow. At one point, the elbow was swollen so much that it looked more like a rattlesnake bite (which I’ve seen, once on a burro’s lower front leg and once on a cat’s hind foot).

It got bad enough that I was within hours of going to the emergency room. Not that I expected them to be able to do much about it, but….

Then, finally, the swelling started to subside. I’d gone to bed around four a.m. (I write all night, every night), knowing that I had to be back up at nine that day. If the elbow wasn’t looking any better by nine, I’d have to go consult the hated M.D.’s at the hospital, since I don’t have a regular doctor (nor want one).

I was up by eight, and the swelling was down just a touch. Likewise, the area of obvious inflammation (reddened area) had shrunk slightly.

Tonight, there’s no evidence of that particular bite left except for a tiny red dot that hasn’t quite finished disappearing. The healing process took a good three weeks to get to this point. The bite on my inner thigh is itching and burning, but I can live with it; the bite on my butt is mostly itching.

For the moment, my southern Arizona chigger bites have deescalated from dangerous back to nuisance, our friends the coyotes are singing their night songs outside, and life is good.