Users Online: 92
Home Print this page Email this page
Home About us Editorial board Search Browse articles Submit article Ahead of Print Instructions Subscribe Contacts Special issues Login 

Previous article Browse articles Next article 
Adv Biomed Res 2022,  11:70

Remission of prurigo pigmentosa after breaking ketogenic diet and resuming regular diet

1 Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences (TUMS), Tehran, Iran
2 Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences (TUMS), Tehran; Department of Dermatology, Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
3 Cutaneous Leishmaniasis Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
4 Department of Dermatology, Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Date of Submission26-May-2021
Date of Decision10-Jun-2021
Date of Acceptance15-Jun-2021
Date of Web Publication30-Aug-2022

Correspondence Address:
Dr. Zahra Nikyar
Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/abr.abr_138_21

Rights and Permissions

Prurigo pigmentosa (PP) is a rare skin disorder presenting as erythematous urticarial papules on the chest and leaving reticulated pigmentation. Although the etiology of PP is unknown, conditions associated with ketosis such as diabetes mellitus, ketogenic diet (KD), and anorexia nervosa are implicated. Herein, we report a 21-year-old woman who developed PP after adhering to a KD and responded to resuming a regular diet.

Keywords: Ketogenic diet, prurigo pigmentosa, treatment

How to cite this article:
Daneshpazhooh M, Nikyar Z, Kamyab Hesari K, Rostami E, Taraz Jamshidi S, Mohaghegh F. Remission of prurigo pigmentosa after breaking ketogenic diet and resuming regular diet. Adv Biomed Res 2022;11:70

How to cite this URL:
Daneshpazhooh M, Nikyar Z, Kamyab Hesari K, Rostami E, Taraz Jamshidi S, Mohaghegh F. Remission of prurigo pigmentosa after breaking ketogenic diet and resuming regular diet. Adv Biomed Res [serial online] 2022 [cited 2023 Feb 1];11:70. Available from:

  Introduction Top

Prurigo pigmentosa (PP) is a rare pruritic inflammatory dermatosis characterized by erythematous urticarial papules. It was first reported in Japan by Nagashima et al. In 1971[1] PP was later coined in 1978.[2] It typically occurs in Asian women of childbearing age, although it has also been documented in other regions and ethnicities as well as in men.[3] The etiology of PP is largely unknown, however, various mechanical, inflammatory, and metabolic factors have been assigned to this condition. Importantly, PP has been strongly associated with conditions that commonly induce ketosis, such as restrictive diets, fasting, and uncontrolled diabetes mellitus. Resolution of PP after resuming a regular diet supported the causative role of the ketogenic state in this disease. In addition, certain systemic conditions including adult-onset Still's disease, atopy, Helicobacter pylori infection, and Sjogren's syndrome have also been reported in association with PP.[4]

The ketogenic diet (KD), a well-established treatment for childhood epilepsy has been increasingly used for the management of obesity and diabetes mellitus. KD is a very low carbohydrate, moderate protein, and high-fat diet that induces hepatic production of ketone bodies through activation of hepatic ketogenesis. During this process, fat is broken down into fatty acids and ketone bodies.[5]

PP goes through three stages; in the early stage, the disease presents as pruritic urticarial plaques or papules clinically and superficial perivascular neutrophilic infiltration in pathology. The next stage manifests as crusted erythematous papules and papulovesicles with spongiosis and necrotic keratinocytes. In the last stage, pigmented macules are seen with lymphocytic infiltrate and melanophages in the papillary dermis.[6]

In this report, we describe a 21-year-old woman who developed PP after adhering to a KD and responded to resuming a regular diet.

  Case Report Top

An otherwise healthy 21-year-old woman presented with itchy skin lesions over the chest and neck evolving for 2 weeks. The rash occurred 1 week after starting a carbohydrate-restricted KD.

The skin examination showed symmetrically distributed erythematous papules interspersed with dark brown pigmentation in a reticulated pattern in the intermammary and submammary regions, and the neck [Figure 1]a and [Figure 1]b.
Figure 1: (a) Prurigo pimentosa: Erythematous papules and plaques on the chest. (b) Prurigo pigmentosa: Erythematous papules on the neck

Click here to view

A punch biopsy was performed; histopathological examination of hematoxylin and eosin-stained tissue revealed acanthotic epidermis with prominent spongiotic vesicles containing lymphocytes and few neutrophils. Papillary dermis revealed superficial perivascular infiltrate of lymphocytes and scattered eosinophils [Figure 2]a and [Figure 2]. Dyskeratotic cells were noted in higher levels of epidermis and exocytosis of lymphocytes and red blood cells were evident.
Figure 2: (a): ×10: Low power examination reveals an acanthotic epidermis with some spongiotic vesicles. Superficial dermis is infiltrated by lymphocytes and few eosnophils. (b) ×100: An acanthotic epidermis with prominent spongiotic vesicles containing lymphocytes and few neutrophils. Papillary dermis revesls superficial perivascular infiltrate of lymphocytes as well as few eosinophils

Click here to view

A diagnosis of PP was made based on clinical and pathological findings. The patient was advised to discontinue the KD and take minocycline.

However, she opted to resume a regular diet without taking the drug. She came to her follow-up appointment after 2 months while all of her lesions were resolved, leaving only light-brown postinflammatory pigmentation on her chest and neck [Figure 3]a and [Figure 3]b.
Figure 3: (a) Her lesions resolved leaving only multiple post-inflammatory hyperpigmentation (PIH) on her chest. (b) Her lesions resolved leaving only multiple PIH on her neck

Click here to view

After 12 months of follow-up since she resumed a higher carbohydrate diet, there has been no recurrence.

  Discussion Top

The term “PP” was first mentioned in the literature in 1978, 7 years after its first description by Nagashima et al.[1],[2]

PP typically affects Japanese women aged 20–30, however, there are increasing reports of the disease in Middle Eastern and Western countries. Less than 300 cases of PP have been published so far.[7],[8]

PP is characterized by erythematous pruritic coalescing papules arranged in a reticulate pattern resolving with postinflammatory hyperpigmentation. Pustular, vesicular, and bullous variants have been reported.[4],[9],[10]

Each stage of PP has distinct histopathological features. The early stage is characterized by a superficial and perivascular dermal neutrophilic infiltration along with papillary dermal edema and slight spongiosis. In the fully developed lesions, a heavier dermal infiltration of lymphocytes, neutrophils, and eosinophils in a lichenoid pattern, reticular degeneration of basal cell layer, and a variable degree of spongiosis and necrotic keratinocytes are seen. In the resolved lesions, a sparse lymphocytic dermal infiltration exists along with upper dermal melanophages.[11]

Although the pathogenesis is incompletely understood, several factors have been strongly associated with the condition, which may be grouped as metabolic (diabetes and ketosis), hormonal (pregnancy and menstruation), and physical factors (skin friction, trauma, and acupuncture).[4]

Ketosis has frequently been linked to PP development in various reports. This occurs with diabetes mellitus, fasting, dieting, anorexia nervosa, hyperemesis gravidarum of pregnancy, and following bariatric surgery, all of which are associated with PP.[7]

It has been hypothesized that ketone bodies play a role in inducing perivascular inflammation, primarily through neutrophils, thus explaining the positive response to medications suppressing neutrophil-mediated processes such as dapsone and tetracyclines. Furthermore, ketone bodies can directly affect cells by causing intracellular damage.[12] Reduced insulin levels, which have been reported to occur after bariatric surgery, may also contribute to the development of PP.[13]

KD is one of the main risk factors for PP. It consists of reducing the carbohydrate content in the diet usually to <50 g/d while increasing the fraction of fat and protein intake. The popularity of this dietary regimen is growing worldwide.[14] As a result, the reports of PP following KD, also known as “keto-rash” have increased on social media. KD is also used for epilepsy, Alzheimer's dementia, Parkinson's disease, brain, and other cancers, obesity, autism spectrum disorder, and endurance athletics.[5]

Bariatric surgeries have been linked to PP in some recent studies.[12],[15] It is conceivable that underestimation or underdiagnosis in bariatric surgery could explain the low numbers of cases of PP. Since such procedures are becoming increasingly popular, physicians should be informed about this complication.

The treatment of PP following KD consists of the resumption of a balanced diet and the adjunction of antibiotics that inhibit neutrophil chemotaxis, such as minocycline, doxycycline, and dapsone.[4],[5],[12] Isotretinoin has also been used successfully in PP.[16]

This case report emphasizes the etiologic role of KD in PP and demonstrates that diet modification alone can be curative for KD-induced PP without the need for any other intervention as reported in a few other studies.

  Conclusion Top

KD and bariatric surgery are currently growing in popularity. When dealing with patients who present with reticulated red papular lesions leaving hyperpigmentation compatible with PP, it is important to inquire about recent diet, bariatric surgery, or other conditions that may cause ketosis. Resuming a regular carbohydrate-rich diet may be recommended as the first step of treatment without an immediate antibiotic prescription. In other words, antibiotics should be kept as a second step or in noncompliant patients, and withdrawal of the KD is sufficient to resolve symptoms with no other intervention.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Nagashima M, Ohshiro A, Schimuzu N. A peculiar pruriginous dermatosis with gross reticular pigmentation [in Japanese]. Jpn J Dermatol 1971; 81:78-91.  Back to cited text no. 1
Nagashima M. Prurigo pigmentosa: Clinical observations of our 14 cases. J Dermatol 1978;5:61-7.  Back to cited text no. 2
Michaels JD, Hoss E, Dicaudo DJ, Price H. Prurigo pigmentosa afer a strict ketogenic diet. Pediatr Dermatol 2015;32:248-51.  Back to cited text no. 3
Almaani N, Al-Tarawneh AH, Msallam H. Prurigo pigmentosa: A clinicopathological report of three middle eastern patients. Case Rep Dermatol Med 2018;2018:9406797.  Back to cited text no. 4
Maco MW, Lee E, Wu Y, Lee R. Treatment of prurigo pigmentosa with diet modification: A medical case study. Hawaii J Med Public Health 2018;77:114-7.  Back to cited text no. 5
Oh YJ, Lee MH. Prurigo pigmentosa: A clinicopathologic study of 16 cases. J Eur Acad Dermatol Venereol 2012;26:1149-53.  Back to cited text no. 6
Hartman M, Fuller B, Heaphy MR. Prurigo pigmentosa induced by ketosis: Resolution through dietary modification. Cutis 2019;103:E10-3.  Back to cited text no. 7
Asgari M, Daneshpazhooh M, Chams Davatchi C, Böer A. Prurigo pigmentosa: An underdiagnosed disease in patients of Iranian descent? J Am Acad Dermatol 2006;55:131-6.  Back to cited text no. 8
Kim TI, Choi JW, Jeong KH, Shin MK, Lee MH. Pustular prurigo pigmentosa treated with doxycycline. J Dermatol 2016;43:965-6.  Back to cited text no. 9
Daneshpazhooh M, Safar F, Barikbin B, Safee-naraghi Z, Asgari M, Chams-Davatchi C. Vesicular prurigo pigmentosa in a 16-year-old girl. Nouv Dermatol 2004;23:599-603.  Back to cited text no. 10
Böer A, Misago N, Wolter M, Kiryu H, Wang XD, Ackerman AB. Prurigo pigmentosa: A distinctive inflammatory disease of the skin. Am J Dermatopathol 2003;25:117-29.  Back to cited text no. 11
Alshaya MA, Turkmani MG, Alissa AM. Prurigo pigmentosa following ketogenic diet and bariatric surgery: A growing association. JAAD Case Rep 2019;5:504-7.  Back to cited text no. 12
Abbass M, Abiad F, Abbas O. Prurigo pigmentosa after bariatric surgery. JAMA Dermatol 2015;151:796-7.  Back to cited text no. 13
Paoli A, Rubini A, Volek JS, Grimaldi KA. Beyond weight loss: A review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. Eur J Clin Nutr 2013;67:789-96.  Back to cited text no. 14
Alsebayel MM, Ghobara YA, Al-Issa A. Facial prurigo pigmentosa after bariatric surgery. Cureus 2020;12:e6909.  Back to cited text no. 15
Akoglu G, Boztepe G, Karaduman A. Prurigo pigmentosa successfully treated with low-dose isotretinoin. Dermatology 2006;213:331-3.  Back to cited text no. 16


  [Figure 1], [Figure 2], [Figure 3]


Previous article  Next article
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Case Report
Article Figures

 Article Access Statistics
    PDF Downloaded138    
    Comments [Add]    

Recommend this journal