They Both Suck: Is That Rash Bedbugs…or Scabies?
On those occasions I say “This looks like scabies…”, you could hear a skin mite fart in my clinic. And, as they do the heebie jeebie headshake, many parents then ask a very good question: “Scabies. That’s better than having bedbugs, right?” Kinda. Sorta. Yeah.
The rashes from each of these insects–and their hallmark itchiness–are almost indistinguishable at first. And yet, each foretells a specific blend of misery and disdain. So, for the rashy and worried, how do we know the difference? And, what to do about it? Read on.
It usually begins like this: A family walks in to an exam room, and even before greetings are exchanged, I am shown a rash on their child’s body. Deep in the well of their worry, parents reel in their toddler by the collar, and draw up her sleeve or pantleg, and present the child to me, bent over their arm like a towel, to inspect areas of redness, bouquets of bumps, or patches of irritation. As a primary care doc, I see lots of rashes–up to a dozen– every day. Most are benign, short-lived affairs, mentioned incidentally (“Well, since I have you here…”). Key info about duration, site of occurrence, contact with affected people, or recent travel helps us narrow down the contenders on the differential diagnosis (aka the diagnostic top ten). Eczema? Allergy? Or something else?
Suspected insect bites, especially those of bedbugs and scabies, bring patients to clinic at a trot after an all night spell of itching, or in a cloud of frustration if they get bounced from school or daycare. In assessing a child w, a little biology, physiology and the sense of the bugs’ M.O. helps identify the parasites no one wants to play host to.
Bedbugs are the more notorious player here. The stigmata of their bite is nothing compared to the stigma of their infestation (arguably, that is well deserved). Bedbugs have come roaring back from near obliteration to near ‘epidemic’ levels of infestation in the last decade. The resurgence of Cimex lectularius largely stems from their evolved resistance to insecticides. And, they are a moving target; bedbugs commute to us to feed.
Bedbugs usually arrive in a new environment (eg your house), having hitchhiked in from another area of infestation (another home, and more commonly nowadays, a store or hotel). Following plumes of exhaled carbon dioxide, sweat, or body heat, these 1/2 cm long, seed shaped critters crawl from cracks in the floors, seams in the mattress, and the jillions of nooks and crannies of a homeplace to make a human meal. Do you have insomnia yet?
Bedbugs are nocturnal, and usually most active just before dawn. They feed with a diabolically clever system of saliva laced with anesthetic compounds. Their bites are painless, and classically are bunched in clusters of three nips (clinicians are taught to distinguish these by their mnemonic pattern of ‘breakfast, lunch, and dinner’). And, if the bedbugs were more fastidious, or had a different mechanism of feeding, the discomfort might end there. Alas: bedbugs drool and leave a scrim of spit as they feed. Over time, repeated exposure to proteins in these materials generates a hypersensitivity reaction. Rash city.
So, in children and older patients, we begin to think of bedbug mischief if and when we see bitemarks or signs of inflammation on exposed areas, perhaps with that distinctive pattern of triplet bites . Bedbugs have a fondness for hands , feet, parts of the trunk or neck peeking out of pajamas, and even on the face. Reactions bloom within minutes to hours, ranging from wee itchy bump(s) ,to fluid-filled blisters at the site of the bite, or patches of hives. And therein lies the rubbing: mild to severe itching (“he was up all night”) begins. By the time a kid with bedbugs arrives in clinic, the bedbugs have long since returned to their secret lair. Bedbugs are almost never found in an affected individual.
Scabies work it differently. Their rashes are caused by a barely visible burrowing mite, known formally as Sarcoptes scabiei. Like bedbugs, scabies’ rashes have been vilified since Classical times for their ability to afflict individuals for extended periods with fiery, pruritic eruptions. It is from scabies, after all, that we get the phrase “the 7-year itch.” Lovely. They are a global phenomenon and bummer–afllicting over 300 million cases a year.
Scabies are entirely dependent on humans for their life cycle, existing on or in the outermost layers of the skin. Unlike the bedbug, which can go up to a year between meals (but who usually feed about once a week or so), scabies can live ‘off-person’ for only 2-3 days. From children to adults, scabies spread from close person to person contact–be it toddler scrums in daycare or romantic activity in young adults. And, scabies may pass between kids or family members via clothing, bed sheets, or shared towels. At any one time, a healthy individual who is infected may host but a few dozen of the little guys on her person. For most people, that is a few dozen too many.
Scabies have their preferences. In infants and toddlers, scabies burrow on the face, scalp, neck, palms, and soles of the feet. In older kids and up to adults, scabies prefer the ‘in-between,’ intertriginous areas, such as the webs of the fingers and toes, the groin, and foldy places at the armpits, wrist, elbows or buttocks. As they munch in their burrow, scabies defecate as they go (thanks, guys!). ”Naive” first timers may merely have small tracks in the skin where the mites are digging away. Sensitized kids can mount a range of skin eruptions, from small bumps to raging pustules. Invariably, these sites become intensely itchy and get worked over by fingernails. While it is possible to take samples from some rashes and investigate for the mites under the microscope, we usually consider the history, examine the pattern of rash (burrow lines? lesions between fingers?), and try a stepwise approach for treatment if either parasite is suspected (or, if we aren’t sure).
Here’s a takehome point. Looking in clinic at a child’s bumps and scratched raw areas may not confirm our diagnosis. For a parent who has gone a few rounds of first aid at home, or even treatment in the clinic, it may be time to do some home investigation. There are methods of searching for bedbugs that are well described online. For some parents, that eureka moment of discovery of a bedbug infestation can be as pivotal as it is exasperating. Hey, given a choice, I’d take scabies.
While all of this is quite distressing (and it is!), scabies and bedbugs pose more of a deep annoyance than mortal danger in the US than in other parts of the world. For the sufferers of bedbug or scabies infection, the biggest concern medically is that of superinfection. Intense scratching and breakdown of the skin creates a setup for bacterial infection, such as impetigo or cellulitis. Findings of tenderness, warmth or spreading rings of redness from bite sites herald badness, and are treated accordingly with antibiotics.
For the those bitten by scabies or bedbugs, the treatment for the irritation is the same: good old ‘supportive care.’ For children over the age of one, oral antihistamines may take the edge off the itch. Soothing baths, with oatmeal may help (they won’t hurt!) and trimming of the nails lessen trauma with scratching. In some cases, topical steroid creams may be used to calm the inflammation for particularly fierce rashes. But really, most parents want to know: how do I nuke these guys into the middle of next week? How does one ‘get them gone?’
For scabies, the answer is relatively simple–we zap them where they are at: on the body. In my clinic, I begin with first line of treatment with a cream containing permethrin. This is safe and effective for kids over two months(while resistance is reported in some quarters, I have not seen it to date). The cream is applied to the body overnight and washed off in the morning. Generally, we treat all members of a household to halt the cycle of contagion. There are other treatments, such as tea tree oil or lindane, but I generally go with permethrin. It works.
To mop up stragglers, we advise parents take affected members clothing and bedlinens and put them in a plastic bag for a week. Or, these items can be washed in hot water (minimum 115 degrees, please). Authorities vary on this, but I advise repeating the whole process in week. Familes can consider themselves scabies free if they see no new lesions after a week to 10 days. Phew!
For the ridding of bedbugs, the answer is harder. As countless blogs and the CDC website attest, the key to bedbug treatment is extermination. There are a variety of traps, special beds and bug nets that people can try probably with mixed results at best. Once infestation is confirmed, families may want to toss infested items (so, think twice about picking up that ‘free’ futon on the curb, ok?) but calling in the pros is the best way to go. Unfortunately, this can be long, harrowing, and sometimes, expensive problem to deal with. Not to mention: Ick!
So then, the difference between a child infected by scabies or bedbugs might be measured least by how bedbug and scabies rashes look (similarly bumpy, but differently distributed) but rather by how parents suffer one scourge over another. While I’d rather have neither, I’d reckon that for now, scabies are the lesser evil.
Photo 1 by JulesEtc
Photo 2 by eimaioveipo
Photo 3 by jeredsimmons
Photo 4 by HardinMD
Cartoon below by me
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