What To Do About Keto Rash (Pruigo Pigementosa)

keto rash pruigo pigmentosa

Is keto rash real and what causes keto rash?

Yes, “keto rash” or pruigo pigmentosa has been described and reported in the medical literature. The first medical article on the rash was in 1971 by Nagashima et al. In the 1990’s, researchers made the correlation between the rash and diabetics in ketosis. Interestingly, giving insulin to these diabetic actually improved the rash. Some research has pointed to pruigo pigmentosa resulting from a a low-grade bacteria infection of the skin with an inflammatory response causing the rash.

It’s not clear on why some people on a low carb or ketogenic diet develop this itchy rash. One theory is that people that develop the rash have had a change in their microbiome and this change in microbiome leads to irritation and inflammation of the skin.

What does keto rash look like?

Keto rash, or pruigo pigementosa has a fairly distinct appearance. In the initial stages, the rash will usually be red (erythematous) and itchy (pruitic) slightly raised lesions (papules). Keto rash is most common on the chest and back and seems to occur more often in women than men.

There are several stages of the rash and in subsequent stages, the rash may become crusty or scaly with small fluid-filled blisters (vesicles). The rash will usually improve or go away after two or three weeks, but some people can have a lacy-like dark pigmented rash once the itching resolves.

How common is keto rash?

“Keto rash” is fairly uncommon. There are a few case reports in the medical literature, but its not a common side effect that has people on the ketogenic diet lined up outside their dermatologist’s offices to be seen for the rash.

Keto rash tends to occur in women and in Asians, but doctors aren’t sure why these groups of people are more likely to experience the rash.

What’s the treatment for keto rash?

It appears that simply lowery your level of ketosis by added back a small amount of carbohydrates may be enough to improve or resolve keto rash. However, if the rash doesn’t improve after a couple weeks, please see your doctor.

Antibiotics such as mincycline and doxycycline have also been helpful in treating some cases of pruigo pigmentosa.

Should I stop my keto diet if I get keto rash?

You don’t necessarily need to stop your keto diet if you aren’t having any other problems. Many times, just adding back a small amount of carbs to keep you in a lower level of ketosis can help improve the “keto rash.”

Should I see a doctor if I get “keto rash”? 

If the rash does not go away or get better with making changes to your diet, then it would be a good idea to have the rash evaluated bu your doctor or a dermatologist

Is there any research on “keto rash?”

There actually is some well-establish medical research published on pruigo pigmentosa (keto rash).

In 1971, Nagashima first described and published a paper on pruigo pigementosa and followed up later with a bigger case report on more patients with pruigo pigementosa in 1978.

Teraki in 1996 reported on 10 patients that have pruigo pigmentosa and 8 of the 10 patients were in some state of ketosis, either diet-induced or from poorly-controlled diabetes. When the patients’ ketone levels were reduced, their rash improved.

Mitsuhashi et al in 2005 wrote about a patient that developed “keto rash” or pruigo pigmentosa from drinking too many soft drinks.

There are also case reports of patients developing pruigo pigmentosa after bariatric weight loss surgery as well as a 17-year old patient that followed a very low-carb diet for almost a year that also developed pruigo pigmentosa/keto rash. When the patients added back some carbohydrates into their diets, the rash would improve.


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  2. Teraki Y TE, Kawashima M, Nagashima M, Shiohara T. Ketosis is involved in the origin of prurigo pigmentosa. J Am Acad Dermatol. 1996;34:257–259. [PubMed] [Google Scholar]
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  6. Alkeraye S, et al Twenty-five-year-old female with sudden onset itchy skin eruption over her upper back and chest three weeks after starting a ketogenic diet Ann Saudi Med November-December 2019; 39(6): 444-445. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6894454/
  7. Michaels JD, Hoss E, DiCaudo DJ, Price H, Prurigo Pigmentosa After a Strict Ketogenic Diet, Pediatr Dermatol Mar-Apr 2015;32(2):248-51. https://pubmed.ncbi.nlm.nih.gov/24372546/

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