Avoid These Foods to Help Treat Prurigo Pigmentosa

Prurigo pigmentosa (PP), also called Nagashima disease, is a rare chronic inflammatory skin condition that causes an itchy rash with vesicles (blisters). The blisters eventually develop into brown spots that appear in a net-like pattern.

PP rash often occurs on the trunk and neck, but it can appear anywhere, including the face and scalp. It is also associated with conditions that produce ketosis (when your body uses stored fat rather than glucose for energy), including restricting food intake and diabetes. For this reason, healthcare providers sometimes refer to it as "keto rash."

This article explains the link between prurigo pigmentosa and diet, which foods can help the condition, and which ones to avoid.

Fried Foods

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Prurigo Pigmentosa and Diet Link

PP is sometimes referred to as a "keto rash" because it is linked with those on restrictive food diets, especially a ketogenic diet. A ketogenic (keto) diet involves eating primarily fat-based foods and significantly restricting carbohydrates. This eating pattern creates a ketosis metabolic state (the body uses stored fat for energy).

Since the diet is effective for weight loss, people often follow it to lose or maintain weight. However, some people also use it to reduce the risk of obesity-related health risks, like diabetes, hypertension (high blood pressure), and heart disease.

Researchers believe this connection may have to do with the gut microbiome (the microorganisms in your digestive tract). Thus, an imbalance in the gut microbiome may impact a person's immune response, leading to PP.

Other Causes

In addition to diet, prurigo pigmentosa has been linked to other conditions, including:

Foods to Avoid

If prurigo pigmentosa is associated with ketosis, your healthcare provider may advise you to discontinue a ketogenic diet. Typically that means you should eat a balanced diet and avoid overloading on refined foods and those that contribute to inflammation, including:

  • Red meat
  • Highly processed foods
  • Trans fats
  • Fried foods
  • Refined flours and sugars

As with any treatment, only modify your diet under a qualified healthcare provider's supervision, like a nutritionist or dietician.

Foods You Should Eat

In addition to avoiding less healthy fats, incorporating nutritious foods is essential in reversing prurigo pigmentosa brought on by ketosis. Namely, reintroducing carbohydrates is key to modifying your diet when you have PP.

Focusing on fiber-rich, complex carbohydrates, primarily plant-based foods, can help rebalance your gut microbiome. Complex carbs take longer than simple carbs (like sweets and refined sugar) to digest, allowing blood sugar to rise more slowly.

Add more nutritious carbs to your diet by incorporating:

  • Starchy vegetables (potatoes, sweet potatoes, corn, beets, squash)
  • Starchy fruits (bananas, dates)
  • Legumes (lentils, beans)
  • Whole grains (whole-wheat bread, rolled oats, quinoa)

In addition, since PP is an inflammatory condition, upping your intake of anti-inflammatory foods could also support healing. Anti-inflammatory foods include:

  • Spices (basil, cinnamon, cumin, curry, ginger, turmeric)
  • Healthy fats (salmon, herring, flax, chia seeds)
  • Fruits and vegetables
  • Dark chocolate
  • Red wine
  • Green tea

Other Treatment Options

In addition to diet modification, prurigo pigmentosa treatment includes medication, such as:

A recent study evaluated treatment outcomes in PP. The systemic review included 115 studies, and among the participants who had changed their diet before coming down with PP, 40% had started a ketogenic diet.

The review also found that corticosteroids were effective 13% of the time, while doxycycline ultimately resolved the condition at 52%. For 3.5% of participants, diet alone resolved the condition.


Prurigo pigmentosa is an inflammatory condition that results in a blister-like rash. The ketogenic diet sometimes precedes the condition, so some call it "keto rash." Some research has investigated the role of reversing ketosis in healing PP. Doing so involves reintroducing carbs and eating an anti-inflammatory diet. One study found limited results with diet alone, but it showed significant improvement compared to medication or diet alone when combined with antibiotics.

A Word From Verywell

While the keto diet is popular for producing quick weight loss results, it does come with risks. That's why it's crucial to work with a healthcare provider when considering modifying your diet, including treating PP. If you're worried that your rash might be PP, it's best to receive a medical evaluation and treatment.

Frequently Asked Questions

  • What are some ways to treat prurigo pigmentosa naturally?

    If PP preceded the keto diet, modifying your diet by reintroducing carbs may help. However, some studies have found diet alone to be only marginally helpful. On the other hand, it is more effective when combined with other therapies, like antibiotics.

  • How long do episodes of prurigo pigmentosa typically last?

    According to one study, PP tended to resolve within two weeks to a month with treatment.

  • What are some things that can worsen prurigo pigmentosa?

    Things that cause PP are the same things that can exacerbate it or cause it to recur. These risk factors include sweat, friction, ketosis, food restriction, pregnancy, eczema, diabetes, Sjogren’s syndrome, and some bacterial infections.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Osteopathic College of Dermatology. Prurigo pigmentosa.

  2. Wong M, Lee E, Wu Y, Lee R. Treatment of prurigo pigmentosa with diet modification: A medical case studyHawaii J Med Public Health. 2018;77(5):114-117.

  3. Academy of Nutrition and Dietetics. What is the ketogenic diet?

  4. Masood W, Annamaraju P, Uppaluri KR. Ketogenic diet. [Updated 2021 Nov 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

  5. American Heart Association. Carbohydrates.

  6. Johns Hopkins Medicine. Healthy eating tips to ease chronic inflammation.

  7. Mufti A, Mirali S, Abduelmula A, et al. Clinical manifestations and treatment outcomes in prurigo pigmentosa (Nagashima disease): A systematic review of the literatureJAAD Int. 2021;3:79-87. Published 2021 Apr 10. doi:10.1016/j.jdin.2021.03.003

By Kathi Valeii
As a freelance writer, Kathi has experience writing both reported features and essays for national publications on the topics of healthcare, advocacy, and education. The bulk of her work centers on parenting, education, health, and social justice.