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This rare skin rash was first described in Japan by a dermatologist, Nagashima. It presents with a pruritic (itchy) red rash that heals within a few days with a reticular pigmentation. This rash tends to occur over the back, neck, and clavicular regions. The cause is unknown.


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Prurigo pigmentosa.

Liu MT, Wong CK.

Department of Dermatology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.

Dermatology 1994;188(3):219-21 Abstract quote

Prurigo pigmentosa is a rare dermatosis with unknown etiology.

It is characterized clinically by severe pruritic red papules and reticulate pigmentation thought to be an entity occurring more commonly in Japan where nearly 200 cases have been reported [1].

Outside Japan, only 7 cases have been described [2-7]. In Taiwan, though geographically close to Japan, no single case of this peculiar disorder has been reported. We herein describe a typical case in a Chinese and review the literature.

GEOGRAPHY More prevalent in Asian patients



Prurigo pigmentosa (Nagashima) associated with anorexia nervosa.

Nakada T, Sueki H, Iijima M.

Department of Dermatology, Showa University School of Medicine, Tokyo, Japan.

Clin Exp Dermatol 1998 Jan;23(1):25-7 Abstract quote

Prurigo pigmentosa (Nagashima), which is not rare in Japan, is an inflammatory disease of unknown aetiology.

The characteristic lesions are pruritic red papules, superseded by reticular hyperpigmentation, characteristically on the back, neck, and chest. We now report a case of prurgio pigmentosa associated with anorexia nervosa.

These findings suggest that the ketosis produced by anorexia nervosa may well contribute to the pathogenesis of prurigo pigmentosa.


Bullous prurigo pigmentosa and diabetes.

Kubota Y, Koga T, Nakayama J.

Department of Dermatology School of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.

Eur J Dermatol 1998 Sep;8(6):439-41 Abstract quote

Prurigo pigmentosa (PP) is a type of inflammatory dermatosis characterized by pruritic, reddish, papular lesions that normally resolve while leaving gross reticular pigmentation. In severe cases however, they may form edematous infiltrative plaques, but no formation of vesicles or bullae is generally found.

We herein present the case of a 32-year-old Japanese male patient with diabetes mellitus, who developed a severe vesicular formation. Minocycline was found to be very effective. In addition, the eruption subsided when the urine glucose and ketone levels were controlled by glibenclamide. The most characteristic feature in this case was the fact that numerous vesicles and bullae were seen both in the beginning and throughout the clinical course.

It therefore seems that a sudden exacerbation of diabetes mellitus was associated with a severe formation of vesicles and bullae. The findings of this case may suggest a correlation between diabetes mellitus and PP.



Prurigo pigmentosa from contact allergy to chrome in detergent.

Kim MH, Choi YW, Choi HY, Myung KB.

Department of Dermatology, College of Medicine, Ewha Womans University, Seoul, Korea.

Contact Dermatitis 2001 May;44(5):289-92 Abstract quote

Prurigo pigmentosa is a recurrent inflammatory dermatosis characterized by pruritic erythematous papules and reticulate hyperpigmentation that occurs most frequently in spring and summer.

The etiology of prurigo pigmentosa remains unknown. Numerous authors have suggested that various contact allergens may be pathogenic or triggering factors, but nearly all attempts to identify an allergen have been unsuccessful.

We report a case of prurigo pigmentosa induced by contact allergy to chrome in detergent, supporting the conclusion that contact allergens such as chrome may play a role in inducing prurigo pigmentosa.


Prurigo pigmentosa.

Gur-Toy G, Gungor E, Artuz F, Aksoy F, Alli N.

Department of Dermatology, Ankara Numune Education and Research Hospital, Turkey.

Int J Dermatol 2002 May;41(5):288-91 Abstract quote

BACKGROUND: Prurigo pigmentosa is a rare inflammatory dermatosis of unknown etiology characterized by recurrent, pruritic erythematous papules and gross reticulate hyperpigmentation. It is seen most commonly among young adult Japanese females. Only 20 cases have been described outside Japan.

METHODS: We report two female, Turkish patients aged 20 and 26 years who had a pruritic rash with the characteristic clinical appearance and supportive histopathology of prurigo pigmentosa.

RESULTS: They were successfully treated with minocycline and doxycycline.

CONCLUSIONS: Prurigo pigmentosa is a relatively new clinical entity, and we believe that a more widespread knowledge of this disease will lessen its misdiagnosis. We find it noteworthy to point out that there may be a predisposition to prurigo pigmentosa amongst the Turkish and Sicilian populations.

Prurigo pigmentosa. Report of a case and review of the literature.

Joyce AP, Horn TD, Anhalt GJ.

Department of Dermatology, National Naval Medical Center, Bethesda, Md.

Arch Dermatol 1989 Nov;125(11):1551-4 Abstract quote

Prurigo pigmentosa is an uncommon skin disease first reported from Japan where it has gained recognition as distinct cutaneous disease characterized by rapid response to dapsone therapy.

Recently, a few reports of prurigo pigmentosa have appeared in the western literature. American-born white man and review the literature pertaining to this unique entity.



Prurigo pigmentosa: a distinctive inflammatory disease of the skin.

Boer A, Misago N, Wolter M, Kiryu H, Wang XD, Ackerman AB.


Am J Dermatopathol 2003 Apr;25(2):117-29 Abstract quote

More than 200 patients with prurigo pigmentosa, a disease described first by Nagashima in 1971, have been reported on in Japan, but only 28 non-Japanese patients have come to notice as of today.

In order to establish reliable, repeatable criteria for diagnosis of the disease, we studied 25 patients with prurigo pigmentosa and reviewed the literature pertaining to it as recorded in another 182 patients.

Clinically, prurigo pigmentosa presents itself as pruritic urticarial papules, papulovesicles, and vesicles arranged in reticular pattern and distributed symmetrically on the back, neck, and chest. Lesions involute in a matter of days, leaving behind netlike pigmentation. Exacerbations and recurrences are the rule.

Histopathologically, prurigo pigmentosa begins with a superficial perivascular infiltrate of neutrophils. Shortly thereafter, neutrophils are scattered in dermal papillae and then sweep rapidly through an epidermis in which spongiosis, ballooning, and necrotic keratocytes are accompaniments. En route, abscesses may form in the surface epithelium. Very soon, eosinophils and lymphocytes come to predominate over neutrophils in a dermal infiltrate that assumes a patchy lichenoid pattern. Intraepidermal vesiculation follows on spongiosis and ballooning and, sometimes, subepidermal vesiculation on vacuolar alteration at the dermo-epidermal junction. As the epidermis becomes hyperplastic, parakeratotic, and slightly hyperpigmented, melanophages begin to appear in the dermis. Studies by immunofluorescence are negative invariably.

Dapsone or minocyclin are effective treatments; both of those agents inhibit migration and/or function of neutrophils. The cause and pathogenesis have yet to be determined. Prurigo pigmentosa is unique among inflammatory diseases of the skin and the singularity of it is manifest both clinically and histopathologically.



Prurigo pigmentosa. Case report with an electron microscopic observation.

Shimizu H, Yamasaki Y, Harada T, Nishikawa T.

J Am Acad Dermatol 1985 Jan;12(1 Pt 2):165-9 Abstract quote

Prurigo pigmentosa is an inflammatory dermatosis characterized by pruritic, reddish, papular lesions and gross reticular pigmentation that occurs mainly on the trunk. Nearly 100 cases have been reported in Japan to date.

We describe a patient with this condition who responded well to dapsone. An electron microscopic study of the reddish papular lesion showed marked intercellular edema and evidence of cellular injury of the basal cells. Direct immunofluorescence was negative.

We stress that this condition is a distinct clinical entity, histologically characterized by a lichenoid tissue reaction as proposed by Pinkus, although it is little known outside Japan.




GENERAL Self-healing and resolves within a few days



Vesicular prurigo pigmentosa cured by minocycline.

Matsumoto C, Kinoshita M, Baba S, Suzuki H, Kanematsu S, Kanematsu N.

Department of Dermatology, Surugadai Nihon University Hospital, Tokyo, Japan.

J Eur Acad Dermatol Venereol 2001 Jul;15(4):354-6 Abstract quote

We present a case of prurigo pigmentosa associated with vesicles that we call 'vesicular prurigo pigmentosa'. The subject was treated using minocycline with good results and no recurrence of the lesions over a 2-year period.

Prurigo pigmentosa: a misdiagnosed dermatitis in Sicily.

Schepis C, Siragusa M, Palazzo R, Cavallari V.

Unit of Dermatology, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy.

Cutis 1999 Feb;63(2):99-102 Abstract quote

Prurigo pigmentosa is a papular pruriginous eruption that leaves a marble-like pigmentation. The majority of cases have been found in Japan. Three new female. Sicilian patients with prurigo pigmentosa were studied. All of them had previously been diagnosed as having different types of dermatitis.

The administration of minocycline, at a dosage of 100 mg/day for 1 month, induced the disappearance of the papular eruption and pruritus in two patients, with an improvement of the gross reticular pigmentation. The third showed no modifications of the clinical picture after 2 months of minocycline treatment, but her condition significantly improved after 1 month of treatment with diaminodiphenylsulfone, 100 mg/day.

These observations allow us to suggest that prurigo pigmentosa might be relatively frequent but misdiagnosed in the Sicilian population.


Prurigo pigmentosa: a possible mechanism of action of sulfonamides.

Miyachi Y, Yoshioka A, Horio T, Imamura S, Niwa Y.

Dermatologica 1986;172(2):82-8 Abstract quote

The patient described here had all the clinical features (itchy red papules and reticular pigmentation) as well as the histological findings (lichenoid tissue reactions) of prurigo pigmentosa, a little-known disorder of unknown etiology, and responded well to sulfamethoxazole treatment.

In order to investigate the mode of action of this drug and thus the underlying pathogenesis of this dermatosis, the effect of sulfamethoxazole on the production of oxygen intermediates (OIs) was examined both in the cell-mediated system and in the xanthine-xanthine oxidase system. It was found that therapeutic doses of the drug significantly reduced the hydroxyl radical levels, one of the most potent oxidants that might cause tissue injury.

These findings suggest the possibility that OIs produced by infiltrated cells are involved in the inflammatory process of prurigo pigmentosa and that sulfonamides exert their anti-inflammatory effects by affecting OI generation which results in protection against lichenoid tissue reaction.

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Last Updated 2/12/2003

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