Blastocystis hominis: Skin Disorders and Gut Infections

blastocystis hominis skin rash byron bay herbalist australian naturopath parasite treatment

Skin issues from Blastocystis infection? It sounds like a stretch but the connection between the gut and the skin has been found and is currently being explored (heavily!) in the scientific community. This article will focus on the connection between the Gut and the Skin and will outline some research that points to Blastocystis hominis as being one possible culprit for skin rashes including urticaria, rashes and lesions.

Blastocystis is a common gut infection worldwide. Anecdotally it seems to have quite a high rate of incidence here in Byron Bay and in Australia generally.

For a primer on the subject – Blastocystis hominis – A Protozoan Gut Parasite


Disease States and Blastocystis

For years the pathogenicity of Blastocystis hominis was debated in the scientific literature. In the last 10 years more and more research has come out validating the potential parasitic nature of the protozoan infection

“Clinical features of illness that have been attributed to Blastocystis spp. are nonspecific and include nausea, anorexia, abdominal pain, bloating, flatulence, and acute or chronic diarrhea. Of these features, the most commonly recorded symptoms among patients are abdominal pain and diarrhea. Symptoms can be variable, ranging from mild diarrheal illness and chronic diarrhea to acute gastroenteritis” (2)

It is still very much up in the air. Is this particular bug a problem like Giradia and Entamoeba histolytica? Is it more like the popular and sometimes troublesome (but not always) Helicobacter pyloriFinally it could simply be a scapegoat. A bug that we blame all our digestive problems on when really the issue is SIBO or food intolerances like gluten, lactose or fructose.

We haven’t quite worked that question out so it is worth keeping an open mind and exploring all options before deciding that Blastocystis is the root cause.

Ok. Let’s get into the real reason you are here. Is there a connection between your skin rash and your positive stool test showing you have Blastocystis?


Skin Issues From Blastocystis Infection

It shouldn’t come as a surprise that there is a connection between the gut and the skin. The connection is a hot topic in the research community at the moment and some interesting correlations are being made between the Gut-Skin Axis.

In one study 11% of people infected with Blastocystis hominis experienced skin issues. Interesting to note the majority of those with both Blastocystis and skin where female (3).

Another case of skin issues from Blastocystis infection described a patient with a Blastocystis hominis infection and chronic urticaria (hives). They found that treating the parasite cleared the skin condition in a matter of weeks (4).

In a third paper three separate case studies of patients with skin issues from Blastocystis infection all presented with skin rashes. All three were eventually screened for parasite infections and all three were found to have Blastocystis hominis. After treatment all three cases of skin rashes resolved (5).

Pretty compelling stuff.

One interesting study looked at the prevalence of Blastocystis infections among patients with active chronic or acute urticaria. Out of 54 patients with urticaria (skin rashes/hives) 61.1% where positive for Blastocystis when screened using PCR DNA based technology. Out of those positive for Blastocystis 21 displayed symptoms of infection and 12 were actually asymptomatic (except for the skin disorder). The study included a control group with no skin disorders and found only 8% infected with Blastocystis. Effective treatment (antibiotics in this case) resulted in the elimination of Blastocystis and 100% cure for the hives.


Gut Skin Connection – Beyond Blastocystis

The study referenced above suggested screening patients presenting with hives that didn’t respond to the standard treament for Blastocystis hominis.

The gut skin connection goes beyond Blastocystis.

Research has found correlations between

The gut-skin axis has been well established in the literature. The work being done now is to iron out the details of how the connection is actually being made between the gut ecosystem and the skin. While this is valuable research I think that we can extrapolate from some of the findings currently being published and look to the gut microbiome for anyone suffering from skin disorders.

Other things to be on the lookout for would include

References and Resources

  1. Blastocystis hominis – A Protozoan Gut Parasite
  2. New Insights on Classification, Identification, and Clinical Relevance of Blastocystis spp.
  3. Do not forget the stool examination!—cutaneous and gastrointestinal manifestations of Blastocystis sp. infection
  4. Chronic urticaria due to Blastocystis hominis
  5. Cutaneous Lesions in Blastocystis hominis Infection
  6. Association of Blastocystis hominis genetic subtypes with urticaria
  7. The gut-skin axis in health and disease: A paradigm with therapeutic implications.
Legal and Affiliate Disclosures: This post may contain affiliate links. That means if you decide to make a purchase through one of these links, I may earn a small commission at no extra cost to you. Learn more here

You may also like


  1. Thanks for the info. I currently have chronic urticaria and I have just been diagnosed with Blasto. So fingers crossed that getting rid of the Blasto will cure my hives!

    1. Well done on getting screened. So many people miss the possibility of a gut infection with skin disorders but the connection seems plausible.

  2. A very interesting read. I have had ongoing issues with my stomach and skin for about 20 years. All sorts of tests left me with a diagnosis of IBS. The last four months I have noticed an overall worsening. Skin flare up and itching – doctor diagnosed school sores. Cramping, Diarrhea, extreme fatigue, uncontrollable sugar cravings but mostly lack of appetite for other stuff, headache, light sensitivity and generally feeling crappy. Recently tested positive for Bacto. Just wish I knew how long I’ve had it although my doctor advised there have been quite a few cases recently. Fingers crossed I’m on the road to better days. I wish this was tested for many moons ago and that it was reportable!

  3. Hi Todd this was very interesting to read.

    Coincidentally my hives started while holidaying in Byron. I have now had chronic Urticaria for close to 5 years. I have also tested positive to Blasto. I have had difficulty getting Drs to see a link between the 2 even though I have presented literature..
    I have been given 3 courses of antibiotics… neg result.
    Tried various herbs issued by Naturpaths Neg result and currently getting Xolair injections. The injections in the past has worked but this time round they are only having minimal effect.
    I try to reduce the severity of my hives by not eating potato/ starches/sugar but again this only reduces the severity!!!
    I’m at a loss as to what to do from here.
    My fingers are crossed that more studies and research funds are issued to resolve this issue.

    1. Hmm, this may be a case of Blastocystis modulating the gut environment enough to allow other bugs to get a foothold. I had a very similar experience (minus the hives and a ton of gut symptoms) I think in the end I was struggling with SIBO the whole time. Do you experience any gut symptoms too? Bloating, loose stools or constipation?

        1. I would look into methane dominant SIBO. The plus is that if you do have SIBO the herbal antimicrobials will target the Blastocystis infection too. Let me know how you go!

          1. Thanks so much Todd,
            Can you recommend a location for SIBO testing who are reputable?
            Kind regards

  4. Thanks for this article. I have had chronic skin issues for nearly two years and today I got told I have Blasto. Should start the course of antibiotics soon and hopefully this starts clearing my skin. I had a comprehensive stool test and will also be getting treated for my dysbiosis once the parasite has left the premises.

  5. Hi Todd,
    Interesting read—my 5 year old son has had this parasite for almost 2 years now (since a Mexican vacation when he was 3). He’s been treated twice with 2 different antibiotics without resolution. He Recently had developed a hive-like rash which gets worse at night. I’ve read the same literature you presented in this article and am interested in finding out if there’s a solution beyond antibiotics as these have proven ineffective for him. Have you heard of anything?


    1. Hi Melissa,

      The best approach would be to assess your son’s gut (history, presenting symptoms, microbiome assessment tools) and then tailor a specific intervention for him.

      I have found that Blastocystis is more of a proxy marker for deeper digestive dysregulation in many patients that are symptomatic. Often times SIBO, large bowel overgrowths and even impaired detox pathways (could all be tied together here) lead to skin reactions.

      Feel free to reach out here – and we can discuss the case further.

      Not the most straightforward answer but the gut is complex!


  6. Hi Todd
    I have recently been diagnosed with Blastocytis Hominis and gut dysbiosis by my functional medicine doctor so am now on a course of antibiotics (metronidazole), antiparasitic herbs, biofilm disruptors and probiotics. Strangely, since starting treatment I have woken up each morning with a new breakout of hives. I only had a couple of breakouts before starting my treatments. Do you think this could just be die-off symptoms?
    Thank you

  7. Hi Todd I’ve been suffering from histidine’s and currently rosacea type 2 with pustules etc!! I get hives and as soon as I eat I get reactions I really need to get this under so trip I’m miserable looking to see how you can help!ty sarah

Leave a Reply

Your email address will not be published. Required fields are marked *

Hello. Add your message here.