Tuesday, September 3, 2013

Scabies I

Figure 1: Scabies mite 
What did you do on your vacation this summer? Laid on the beach or hiked in the mountains maybe. Me? I got scabies (Figure 1). I'm sure at least a few of you saw this blog post coming. Since I found out that all these little bumps on my skin were scabies and not bed bugs, I've been reading all about the little fu-, um, critters. My conclusion is that they're disgusting.








Symptoms of a scabies infestation/ infection*
Figure 2: Scabies burrow 
(Source: my leg)
  • Rash
  • Red bumps or papules, they can look like mosquito bites or little tiny bulbous blisters that ooze clearish liquid if you scratch them... and you will because...
  • Itchiness. Intense itchiness. These guys aren't messing
  • around. 
  • Sleep loss to due itching. (The itch tends to be worse at night.)
  • Burrows, sometimes difficult to find but often in between fingers or toes (Figure 2)

Scabies are tiny parasitic arachnids, called the Sarcoptes scabiei mite. They've been bugging** humans for at least 2,500 years. The male mite bites your skin and causes pimple-like bumps (Figure 3). Males aren't too terrible because they just hang out on top of your skin, bite a little, do the nasty with the females, and then die. 

The females, on the other hand, get preggers and use enzymes to dissolve the outermost layer of skin, called the stratum corneum, and then eat their way underneath it.  They like to lay their eggs there, presumably because it's a nice safe place away from danger. While under the skin, the females crawl a little and lay more eggs, then crawl a little and lay more eggs, pooping along the way. This burrowing behavior is what causes the characteristic curvy lines of bumps (Figure 2). 

Mites crawling under your skin sounds itchy, huh? It can be but the real deep-down-drive-you-crazy itch actually comes from an allergic reaction to the eggs and feces. Allergies take awhile to develop so you can have scabies mites on and in your skin for 2-4 weeks without showing any bumps or itchiness. Unfortunately, they are there and you're very contagious during that time. This means I probably didn't get scabies on my vacation. It just seemed like it because the symptoms began during my vacation. It can be difficult to pin down where (or, more likely, who) your scabies came from because of this. As with other allergies, re-exposure to the allergen will produce a reaction much faster, usually within 24-48 hours with scabies because your immune system is already on the lookout for the antigens.

Figure 3: Scabies bump from a male bite maybe 
(the literature is unclear on this). (Source: my leg again)
If a scabies infection isn't caught quickly, the eggs hatch and the little baby scabies mites come out of the skin just long enough to mate. The impregnated females dive back under the skin to repeat the cycle, which takes about two weeks. Thankfully, only about 1% of the immature mites, called nymphs, live to adulthood. It's surprising, but in a classic case of scabies there are only 10-15 mites on any one person. How such a small number of mites can cause so much frustration and itching is impressive but what you really want to know is how to kill them.

There are two options for treatment: a cream and a pill. The cream contains permethrin (5%), which is used at a lower concentration (1%) over-the-counter called Nix for lice. The cream is slathered all over the body from the neck down usually before bedtime. The cream has to stay on for 8-14 hours in order to kill off all the adult mites. Permethrin works by disrupting neuronal transmission.*** It's 2550 times more effective at disrupting transmission in invertebrates, which are animals without a spinal column, than in humans. It's also poorly absorbed by the skin and metabolized quickly by the liver to non-toxic compounds. This makes short-term permethrin treatment safe for humans at low doses.

The pill is called Ivermectin and is usually reserved for more severe cases of infestation, most notably Norwegian crusted scabies which is something you probably don't want to google for images. I cannot imagine how horrible it must be to have an infestation progress to that stage. Thankfully, crusted scabies are less itchy but unfortunately, are much harder to get rid of. Ivermectin also works by disrupting neurotransmission but in a slightly different way.****

Figure 4: Contact dermatitis. 
(Source: you guessed it, same leg)
Which is better: permethrin or ivermectin? At first glance, the scientific literature favors permethrin but several weeks after treatment with either, the cure rates were not significantly different in two studies. A pill seems easier but the cream may work faster, possibly because Ivermectin acts on the adult mite's central nervous system and can't kill the eggs or the newly hatched nymphs. The cream, I found out firsthand, also has the unfortunate side effect of causing contact dermatitis, aka an itchy rash (Figure 4). No matter what the treatment to actually kill the scabies, antihistamines (benadryl) and topical corticosteroids (cortizone) help immensely to reduce the itch. Benadryl has the added side effect of knocking you out so you can sleep your way through the nightmare that is scabies infestation. Using topical corticosteroids for longer than a week or on a large surface area of the body is not recommended though because it can thin the skin, a condition called steroid atrophy.

So far, I've described the standard information out there about scabies albeit hopefully in a more entertaining format. But it's not enough information for me because I always want to know WHY. In my next post, I'll attempt to explain some of the whys, such as: Why do I need to use permethrin cream at night? Why do scabies itch more at night? Am I going to get scabies from my friend who I ate dinner with the other night who had them? Inquiring minds want to know.


*The term infection seems more benign but I think the technically correct term in this case is infestation. Ew.
**It's funny because some pedant is going to want to correct me and say that arachnids aren't bugs. To that I say, hah! 
***More detail? It causes prolonged depolarization of sodium channels. 
****Ivermectin probably works through ligand-gated chloride channels as in the nematode but the mechanism hasn't been studied in the scabies mite yet.

I am not a medical doctor, none of this is intended as medical advice, and I cannot diagnose you in the comments. If you are concerned about your health, please see your physician.

42 comments:

  1. Thank you for this post. Did you ever get rid of them? We have had them for months, mainly due to the other family members not treating correctly. How did you finally get rid of them?

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  2. Yes, I was prescribed the permethrin cream and used it overnight once and then again one week later. After each time I washed all my sheets, blankets, and clothes I'd worn in hot water for good measure. Good luck getting rid of them!

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    1. Um, what about your pillows?

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    2. I bought a new pillow because I needed a new one anyway. Just bagging it up for a few days and using another one in the meantime (and then bagging that one up for a few days) would be fine.

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  3. Have you heard of any association with taking medication for scabies and onset of Parkinson's Disease? If I google "permethrin" and "Parkinson's Disease" I get some very disturbing results. The Wikipedia page seems to show two conflicting studies.

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  4. I saw it mentioned in a few papers when I was reading the literature to write my scabies posts. The scary study cited in the Wikipedia page from 2002 used intraperitoneal (into the abdomen) injections of the chemicals into mice several times over a few weeks. This isn't comparable to human exposure via permethrin cream. Permethrin is very poorly absorbed through the skin and the dose of the cream is very low. In addition, people aren't using permethrin chronically for a long period of time. Even if they're reinfested, it just two treatments one week apart.

    On the other hand, if someone works with permethrin in an environment where they would ingest a lot of it, it could be harmful over the long-term.

    I hope that helps!

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  5. just wanted to thank you - your writing was very well informed but made me crack up with laughter, which i need right now as my body is stinging from the bleach water solution i sprayed on it. permethrin is on the way. THANK YOU. the bleach is dissolving the sores, but a lot of pure bumps are left after one day of bleach water treatment and i assumed they were eggs that are about to hatch - but you're saying they are male bites! good!!!! THANK YOU

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    1. Gah! Bleach water! People, please do not do that! I'm glad you're getting permethrin!

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  6. My apartment complex came down with a bad case of these years ago. Luckily it was taken care of very quickly and there wasn't too much damage, but I do remember a few nights of unstoppable itching, sleep loss and paranoia. I still don't like to feel something moving across my arms or legs. I am glad you made it out alive!

    Kristy Harrington @ Antac Pest

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    1. Thanks! It really, really sucked and I hope to never have them again!

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  7. Hi, and thanks for your blog, I'm from Italy, and I have a question, how many time start your symptoms of scabies? Thanks and sorry for me English

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    1. I've only had the symptoms of scabies once. If you mean how long does it take from being exposed to having symptoms, it is approximately 2-4 weeks. Does that help?

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  8. Yes thanks, then when you have the first symptoms around 2-4 week ok thanks, the itchy is very hard? Thanks

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    1. Yes, VERY itchy! Especially at night.

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    2. Thanks friend, for all but I have a last question 12 weeks ago I have a massage with a friend (I don't know if she have a scabie), now 12 week ago I have a lot of itchy, it's possible scabies? My dermatology say no, he say 12 week I have a lot of lesson in my body, but I don't know if always the symptoms stars 2-6 weeks.... In your travel when star yous symptoms? 2-4 weeks? When you had the first symptoms.. Have a lot of lesson? Thanks

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    3. As far as I know, your dermatology is correct. 12 weeks is too long after exposure to start seeing symptoms. However, maybe you were exposed to them in the weeks after the massage?

      I was never able to pinpoint where I got my scabies from so I don't know from personal experience how long it takes for the symptoms to show up, I just what I've read from medical and research information.

      Your dermatologist should be able to tell straight away if the lesions you have are scabies lesions or not. The wavy trails are very obvious as shown in Figure 2 of this post.

      Good luck!

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    4. Thank´s for all friend, but don´t know when could start?
      an approximation ? I 'm really scared , because a dermatologist told me I could start 6 months later, but instead other dermatologists told me that 6 weeks is enough to have the body covered with wounds , and 12 weeks have passed already be full of wounds, THANKS FOR YOUR HELP

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    5. I don't know what else to tell you. A doctor will have to take a look for you. Sorry!

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  9. Your posts on the "fun" topic of scabies were great, thanks so much! I've found it hard digging through the internet for reputable scientific information on this unfortunate topic since I was diagnosed with it myself I guess about 2 months ago now and you've seemed to really round up all the solid facts/information that actually seem accurate and not overly riddled with paranoia.

    Long story short, I got re-infested somehow a couple weeks ago after my first round of treatments and my doctor prescribed me with another tube of Permethrin. Quite shitty and annoying, because I felt extremely cautious about the treatment process and wouldn't put a piece of clothing on me that wasn't washed in the last day.

    I had a question though and perhaps could be related to how I got re-infected, this is something that I've read conflicting reports on based on where you read the info. I'm wondering what you yourself did since you successfully treated yourself so quickly or if you came across any info on it. How do you deal with your shoes?! I also asked my dermatologist this and his answer was "nothing needs to be done, there's not really a surface they can live on in shoes".

    However, I'm not so sure I buy this for some reason and there's no scientific studies I've found online on where scabies like to hangout outside of a host or how the hell they move around from thing to thing. Like what if you were wearing your shoes without socks, totally could have gotten a mite in your shoe I assume because of that? I have quite a few pairs of shoes that I rotate depending on what day it is, so there's really no "safe" pair that I hadn't worn while infected. Regardless I tried my best to change shoes to a pair I thought I hadn't worn in over 3-4 days (the common theory of life span for a mite living outside of a host) post applying the Permethrin.

    I put on some leather boots and frankly, there's really nothing I could have done to clean them before wearing them. Pretty sure I also hadn't worn them in over a week, they were just sitting out in my closet the whole week and not sealed in a bag. Another question is, does shit really have to be stored in a sealed bag or can I just leave the jacket I wore hanging by itself for two weeks because I also did that for a jacket before wearing it again.

    Who knows though, I'm just trying to figure out where things could have went wrong and try to make it out of this second treatment without getting re-infected. Any input or info you might have is amazing and thanks so much again! Truly one of the most annoying things I've ever dealt with and trying to stay level headed through all of it is a test of ones mental toughness. It's rad you keep checking the comments on this old post of yours, you're a true life savor to everyone who's dealt with this nasty issue :)

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    1. Wow, thanks!

      I did bag some things up (wool sweaters that can't be washed in hot water) but I didn't bag up my shoes. I just avoided wearing my main pair for about a week so that if there were any scabies on there they would die, which would happen no matter if they stayed on/in the shoe or if they crawled off onto the floor.

      I talked about how they get around in my second scabies post, which you can find here: http://sicknessisfascinating.blogspot.com/2014/02/scabies-ii.html. Short answer: they crawl, very slowly.

      Thanks for the feedback! This is my highest viewed and commented on blog post and I get notification of each new comment. I'm glad it helps!

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  10. Thanks so much for this post! It really gave me some answers I needed. I do have a question you didn't already answer. How long did it take for the itching to stop after treatment with permethrin? I used it the night before last but still feel itchy. It's better but not gone. Just wondering if I need to use it again tonight.

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    1. Don't use it again tonight unless your doctor said to. Permethrin can cause contact dermatitis, which is also itchy. My itchiness didn't go away completely for a couple of weeks and Google says it can last up to three weeks. The good news is that it gets slightly less itchy as time goes on. If you aren't already using itch cream and taking Benadryl I would definitely recommend that. Good luck!

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    2. Thank you so much for taking the time to reply and for the 2 blogs on the subject. After reading them and all of the comments, I feel like I have a better grasp of how to handle what's going on. Of course I would have been much happier not needing this info!!!

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    3. No problem! I'm so glad they were helpful! I, too, wish I hadn't had a personal reason for writing the posts but I'm glad I did!

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  11. I have a question on where exactly to apply the permethrin cream....can it be used on genitals? I hate to ask this, but honestly, that is where I have a lot of my itching. My daughter moved back home with my grandson about nine months ago & brought this nasty "bug" with her. We've all done the treatment twice, four applications total, and are infested again. We've washed everything from sheets to pillows to clothes to spraying a bed bug spray, which has permethrin in it, on our mattresses & furniture. I even bought a new bed & mattress, though I was in the market for one anyway. The only thing I can think of is 1 - my daughter is putting my grandson's diaper back on too early, & the cream gets rubbed off, or 2 - her dog is reinfesting us. I've read both of your posts & you mentioned that sarcoptic mange & scabies are from two different mites. Have you ever looked at them under the microscope or compared pics of the two? THEY ARE EXACTLY THE SAME. Whether scabies can "live" on a dog or not, I'm convinced that the dog is passing the mites back & forth with my daughter & grandson. The dog sleeps with them. Also, if the mites can't live on the dog, that kinda makes sense cuz she doesn't look like a dog with sarcoptic mange. Idk. I'm just so frustrated, as I'm sure you know. I have greatly appreciated your posts about this matter. Very informative & witty! Ik you're not a doc, but many docs wouldn't even give us a skin scraping, even at the ER! You've given way more info than all 3 of our docs combined, lol. Anyway, thank you. :-)

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    1. Permethrin should *not* be used on the female genitals! I don't know about male. Please see your doctor if you've used it on your genitals.

      What you've likely seen are mis-labeled pictures on the internet because mange and human scabies have fairly obvious defining characteristics. However, mange can possibly live on human skin for a couple of days before dying so maybe the dog is reinfesting the kids on a nightly basis. Check with your vet and your doctor about this!

      Skin scraping is rarely necessary because scabies infestation is common and the rash and burrows are definitive to a diagnosis. Doctors see it all the time.

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  12. Thank you so much for this blog. I've been reading about scabies all day to try and understand what is happening to me and how to successfully treat myself, my family, and clean our home to avoid reinfestation. We all have our cream on for the night and I'm going to be doing a lot of laundry tomorrow morning before everyone bathes. I have two questions. 1) is vacuuming the upholstery and carpeting enough? We spend a lot of time every day on the couch and I'm worried about mites hanging out there overnight and getting back on us tomorrow. 2) is bagging the hard to launder items necessary or can I store them in another room and keep the door shut for 3 days? Thanks again! This blog is a light in the darkness.

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    1. Thanks for the comment! Vacuuming my couch was enough but that's just one person's anecdotal evidence. If you're really worried then you can avoid sitting on it for a few days. Storing the items in another room is fine. I think bagging is just an extra precaution so that no one touches the items in those few days.

      Good luck!

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  13. Thank you very much for all the information! I really appreciate you post.

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    1. Thanks so much for sharing your post, reading other people's nightmares and stories can really take a mental toll but this was really helpful! We were diagnosed a couple days ago, I have terrible OCD and anxiety over cleanliness and bugs, low and behold this happens. To say the least, it's been a struggle. We have completed our first round of permethrin and while my symptoms were not near as bad as my husbands, I'm now terribly itchy and have contact dermatitis on my arms, back, and stomach. Ive washed our clothes and sheets daily, vacuumed and even steam cleaned the carpets because my mind won't let me think that our home will ever be totally mite free and clean again. In your experience if one gets scabies, are they more likely to catch it again someday down the road? If properly cleaned are infestations in the home able to be totally cleared after 2 permethrin treatments?

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    2. The contact dermatitis sucked! Using cortisone cream and benadryl really helped me. From what I've read, if you are exposed to and get scabies again the allergic reaction occurs sooner because you're already sensitized to them. However, I wouldn't say you're more likely because it just depends on where/how you were exposed and if you'll be exposed again (either from the same place or another). Your home should be fine after 2 treatments and heavy cleaning!

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  14. Hey I hope you all are doing well and scabies-free. OK, I am 99% sure I got scabies and where (who) I got it from. I got it from a girl I liked so much and after a one night stand realized she was itchy while sleeping. That turned the red alert on. I got scabies before, years ago from a trip to South America so this time I developed symptoms within 24 hours (two itchy pink bumps in my left wrist and random itch in the scalp, ears and even the nose) so I remembered how bad it felt (I still have scars in my legs) and ran to the drugstore. I used permethrin two days in a row all over my body (even scalp and ears) and did laundry but I am not sure if it worked cause I was still a little itchy. Days later after reapplying permethrin I got some new small red bumps but this time mostly in my arms (like 10 in each arm) and random parts of my body (1 in my right leg, 1 in my left leg, 2 in my lower back, 3 in my shoulders and like 3 in my neck), some of them itchy at times and other don't itch. This number of bumps didn't break out during the first days after I got infested so this morning I took ivermectin pills (two pills with 6mg each one) and the itch is still there, in random places all over my body (legs, scalp, ears, eyebrows, ankles). The bumps are there too, but they don't look that bad, so the itch is the main concern. I don't know if it's the mites that survived and took revenge, or if it's the famous post-scabies syndrome (I can't remember if I had it the first time I got scabies) or if it's the permethrin irritating my skin or if i'm going nuts. Another possibility is that 1%... maybe I don't have scabies, maybe it's something else. Should I reapply permethrin? Last time I used was like 5 days ago. Any thoughts? Thanks. -

    Permethrin Junkie

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    1. I'm not a doctor so I can't say. See your doctor again and they can verify the diagnosis of scabies and/or tell you what the new bumps are (probably, random rashes are hard to diagnose).

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    2. I really appreciate the info in this post. About a week ago I noticed some very tiny dots on my arm, around my elbow that were itchy. I honestly thought it was dry skin and thought nothing of it. Then the next day, I realized my other arm was itchy in the same place, and that the original arm had larger bumps.

      I started applying my roommates prescribed rash creams on my arms, thinking I must have come in contact with something that my skin didn't like. But this problem persisted each day, only getting worse... and appearing worse each day.

      Finally, yesterday (after a weekend out of town) I took myself to urgent care, because as I was researching rashes online and discovered scabies... which totally freaked me out. This is seriously my worst nightmare. I'm so scared that I will never get rid of this! Sure enough, the doc thinks it is scabies and prescribed a cortisone cream alongside the permethrin. She said she didn't see the typical "mite burrows," but that the rash (which is now covering both elbows and forearms, some parts of my shoulders and my upper arms, appears to look very much like scabies. She did not actually test for it though.

      Last night, I applied my first treatment of the permethrin. Today, I've been scouring my house and cleaning absolutely everything. I made sure my roommate also requested a prescription from her doc to prevent this from spreading or continuing on.

      My reason for commenting is because I had a question about the recovery period. I know that the itching can get worse, but do the bumps continue to manifest and get worse... even though you are treating it? Today... I found a few of the infamous "s" shaped burrows. These were not visible at all yesterday. Did these occur after treatment, or is it possible that they've just surfaced?

      I am so worried that this is a bad case of scabies, and that I'm not really killing them off... despite following all directions and taking every precaution. This rash is the worst on my elbows and the back of my forearms - so at least I can't see it as easily, because it looks so hideous. I also don't understand why the bumps are so gigantic on my elbows.

      Thank you for any insight on this.

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    3. Yes, the characteristic bumps can continue to appear for several days after treatment. They may even seem to get worse. I think this is due to it being an allergic response to the feces, eggs, and -ew- probably to the dead scabies.

      Hang in there! I hope you feel better soon!

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  15. I've exhausted many treatments over a few months and I even moved and left everything behind. They don't seem to be in the places they were (my upper thighs , waist , between fingers) But I believe they moved into my scalp a while back. So now today I have 36% permethrin combined with a little coconut oil , rubbed into my scalp/hair.
    I've also been taking the horse paste ivermectin quite often. My gf that I kept a bay for a while has no symptoms. I may have lost my job because I was so exhausted I told them I could not go to work to due to a medical condition. My life has taken a sharp nosedive and I'm to the point of I research suicide methods nightly. I have no insurance. Ironically I quit my insurance because I was doing quite fine and it was so expensive. And then this came out of nowhere.

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    1. If you're no longer having symptoms where you were and only having itchiness on your scalp you should see a doctor again because it is likely something other than scabies. Using products not meant for humans is not safe and a doctor can prescribe something more appropriate. I hope there is a free or low cost clinic near you. Good luck.

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  16. I had scabies back in 1999 to 2001. A 2 year nightmare. I just gave birth. I moved in my friends brand new moble home. My mother gave me a bed, and an dresser that she had in her apartment. I'm really not sure where I got scabies from there was not pin pointing it down. I have a couple theories where it came from. I either got it from a skirt that I bought from k mart on the sale rack that I know possibly it came from someone's home that had the infection, or it came from my babies daddy at the time. My daughter was an infant she was itchy all over I took her to the doctors he said eczema so I did the cream and oatmeal bath. I had it too thought . I got so bad I had to take my daughter to the ER they confirmed it as scabies. I was so upset, how can I get this? Did the skin treatment on the both of us. Washed all clothes, bedding, and vaccummed. It went away for about a couple months. And then we got infected again. I moved from my friends house left my bed and dresser. Unfortunately my friends got the infection as well. So make a long story short the only thing that got rid of it was getting rid of all clothes live in a hotel for a week do the treatment. Get a new place to live and go to that new place with nothing. Only the clothes on your back. If I ever get those bastards again I burn my house down.

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  17. Wow, that sucks! I never found out where I got mine either but I haven't had them again. I hope that's the end of it for you!

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