Prurigo Pigmentosa after a Strict Ketogenic Diet

Abstract

Prurigo pigmentosa (PP) is a rare inflammatory dermatosis of unknown cause characterized by a predominantly truncal eruption of pruritic erythematous papules in a reticular pattern, resolving with hyperpigmentation. PP is twice as common in girls and women, and the mean age at onset is 25 years. Diagnosis of PP is challenging and is aided by characteristic histopathologic findings. We report a case of PP in a 17-year-old white boy. The eruption arose during strict adherence to a ketogenic diet.

Facial Prurigo Pigmentosa After Bariatric Surgery

“…The term "prurigo pigmentosa" was first mentioned in the literature in 1978, seven years after its first description by Nagashima et al [1,14]. PP is most commonly seen in the third decade of life, with a female-to-male ratio as high as 6:1, and has been previously described in more than 300 cases, largely affecting the Japanese and East-Asian populations [15][16][17][18]. However, increasing reports of PP have been observed in the Western countries, and, more recently, in the Middle East, which might be reflecting the increased awareness about the condition [9][10][11]15].…”

Pruritic papulovesicular dermatosis with reticular hyperpigmentation

“…As regards disease-related PP, treatment of the associated disease led to clinical improvement in patients with Helicobacter pylori infection or adult-onset Still's disease but failed to do so in a patient with Sjögren syndrome [7]. Remarkably, PP often appears to be related to dietary changes leading to ketosis, including severe weight loss, anorexia nervosa, or strict ketogenic diets without carbohydrates [10][11][12]. In almost all diet-related cases, PP improved after resuming a balanced diet.…”

Prurigo Pigmentosa: An under‐recognized inflammatory dermatosis characterized by an evolution of distinctive clinicopathological features

“…Depending on the stage of development, the histopathological differential diagnosis includes dermatitis herpetiformis, irritant contact dermatitis, linear IgA disease, neutrophilic dermatoses, erythema multiforme, adult onset Still's disease, as well as various spongiotic and interface dermatitides. 1,3,6 Although the reticulated pigmentation can be clinically impressive, histologically it is non-distinctive, showing only a superficial perivascular lymphocytic infiltrates associated pigment-laden macrophages, which is indistinguishable from other inflammatory dermatoses resulting in postinflammatory hyperpigmentation. 1 Therefore, accurate diagnosis requires detailed clinicopathological correlation with attention to the dynamic clinical and histopathological course of the disease.…”

“…The etiopathogenesis is unknown, but various hypothesizes have been postulated and include friction, contact allergens, photosensitivity, infectious agents, and metabolic disorders such as diabetes mellitus, fasting, anorexia and ketosis. 1,3,5,9,11,14 To date, none have shown a consistent causal relationship; however, symptoms are often exacerbated by hot weather and/or sweating. 1,5,13 There have been a few case reports of PP associated with other diseases, including autoimmune conditions, adult-onset Still's disease, atopy and pregnancy; however, these associations may merely be coincidental rather than causative.…”

“…The etiopathogenesis is unknown, but various hypothesizes have been postulated and include friction, contact allergens, photosensitivity, infectious agents, and metabolic disorders such as diabetes mellitus, fasting, anorexia and ketosis . To date, none have shown a consistent causal relationship; however, symptoms are often exacerbated by hot weather and/or sweating .…”