Prurigo pigmentosa: role of ICAM-1 in the localization of the eruption

Promyelocytic Differentiation in Infiltrates of Prurigo Pigmentosa: An Analogy to Histiocytoid Sweet Syndrome

Prurigo pigmentosa (PP) is a rare inflammatory dermatosis of unknown etiology. Young women are affected most commonly. Clinically, heavily itchy papules erupt mainly on the trunk healing with residual reticulate pigmentation. Histopathologic descriptions of PP are somewhat controversial. First, PP was reported as lichenoid-interface dermatitis, and later, neutrophils were recognized as the characteristic feature, and the variation in histopathologic patterns was interpreted as a time-dependent phenomenon. Immunohistochemical studies on PP are rare. Biopsies of 5 patients with clinically typical PP were examined histopathologically, and infiltrates were characterized immunohistochemically: myeloperoxidase, CD11c, CD68, CD4, CD8, tryptase, and langerin. In all cases, myeloperoxidase-positive cells with band forms of nuclei and with histiocytoid cytomorphology were identified. They were seen in the epidermis (4/5) and in the dermal infiltrate (5/5). On staining with CD11c, myeloid dendritic cells could be demonstrated in the infiltrate (5/5). In conclusion, myeloid progenitor cells are part of the infiltrate in PP, and they may sometimes be more numerous than mature neutrophils, akin to the situation in histiocytoid Sweet syndrome. This supports the classification of PP as a "neutrophilic dermatosis." In biopsies of suspected PP in which mature neutrophils are sparse, the section should be searched for neutrophilic band forms and histiocytoid promyelocytic cells. Immunohistochemical staining with myeloperoxidase helps to identify such cells and may enable a diagnosis of PP even when mature neutrophils are few.

Prurigo Pigmentosa-Report of 3 Cases From Brazil and Literature Review

Prurigo pigmentosa (PP) is a rare inflammatory disease of the skin of uncertain etiology first reported in Japan. It is typified by recurrent eruptions of itching urticarial macules, papules, vesicopapules, and plaques with a reticular arrangement that quickly resolve leaving a net-like pigmentation. The disease presents specific histopathological features. Herein, 3 cases of PP in Brazilians with no Japanese ancestry are reported and a revision of all previous English-language case reports indexed on PubMed is provided. Two articles with original case reports not listed on PubMed were also included. Our patients are 2 women and 1 man at the ages of 39, 33, and 22 years, respectively. All 3 presented findings in consonance with previous cases of PP and were diagnosed based on clinicopathological correlation. They were successfully treated with oral minocycline or doxycycline. In our literature review, a total of 210 previously reported cases were included. Although PP seemed to be restricted to Japanese patients in the first years after its recognition, the geographic boundaries of the disease are continuously expanding. Korea responded for 83 previous cases and Japan for 53. The mean age was 24.4 years, with 84.3% of the cases occurring between 11 and 30 years of age. The female/male rate was 2.6 and the most affected anatomical sites were back, chest, and neck. We do believe that the rarity of case reports in western countries may represent lack of awareness about the disease by dermatologists and dermatopathologists in these regions.

Prurigo pigmentosa: a clinicopathologic study of 4 cases from the middle East

Prurigo pigmentosa (PP) is a rare inflammatory dermatosis originally reported in Japan. Since then, most reports have originated from Asia, and to a lesser extent from Europe. Although the pathogenesis remains unclear, it is now established that PP is linked to ketoacidotic states. Four patients diagnosed with PP were identified from the dermatopathology database at the American University of Beirut Medical Center between January 2009 and December 2013. Clinicopathologic findings in the 4 patients were similar to those previously reported in the literature. The patients were all female with a mean age of 23.5 years. They all presented with itchy erythematous reticulated papulovesicles/plaques leaving variable reticulated brownish patches. Two patients had, in addition, annular lesions arranged en cocarde and pustules, respectively. In 3 patients, the rash was associated with fasting or dieting. The rash had a predilection to the trunk and proximal part of the upper extremities. One patient had intergluteal area involvement. Two biopsy specimens revealed psoriasiform hyperplasia and neutrophilic exocytosis mimicking psoriasis or an impetiginized spongiotic dermatitis. One biopsy specimen exhibited a mild superficial perivascular lymphocytic infiltrate with ballooning and reticular degeneration, a picture mimicking a viral exanthema. Another biopsy specimen exhibited a picture similar to chronic spongiotic dermatitis. Although mostly described in Japan, PP has been described much less frequently in the Middle East region likely due to mis/underdiagnosis. Therefore, increased awareness is necessary especially because fasting is a common religious practice among Arab countries. Further investigations are necessary to better understand the etiopathogenesis of this rare entity.

Prurigo pigmentosa associated with an atopic diathesis in a 13-year-old girl

We report an Italian prepubescent girl with the typical clinical and histologic features of prurigo pigmentosa associated with an atopic diathesis. The dermatitis disappeared after treatment with minocycline, leaving a brown, reticulated hyperpigmentation, with no recurrence. The association with an atopic diathesis could justify, in this instance, the major susceptibility to environmental factors claimed by some authors as triggering factors for prurigo pigmentosa. To our knowledge, this is only the second occurrence of this disease in a prepubescent patient reported in the literature.

Skin diseases described in Japan 2004. In Japan beschriebene Dermatosen 2004

During the last century of modern dermatology, more than 30 skin diseases have been described first by physicians from Japan. Many of those conditions were disorders of pigmentation and keratinization, which are quite common in Oriental patients. Since the late 1940s, a number of skin diseases first reported in Japan have gained attention internationally among them being Kimura disease, hypomelanosis of Ito, Kawasaki disease, adult T-cell leukemia/ lymphoma, eosinophilic pustular folliculitis, prurigo pigmentosa, and Ofuji's papuloerythroderma. In this article, we review skin diseases that were first established as distinct entities in Japan, in order to familiarize readers of the Western literature with these conditions.

Prurigo pigmentosa: a distinctive inflammatory disease of the skin

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

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 from contact allergy to chrome in detergent

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 rôle in inducing prurigo pigmentosa.

Skin diseases first described in Japan

Over the 90 year history of dermatology in Japan, about 30 skin diseases have been first described by our colleagues. Although some of them have become well known internationally, many of them are less well known outside of Japan. In this article, we introduce those conditions first described in Japan which are lesser known but have international significance.

Immunohistochemical evaluation of epidermis overlying basal cell carcinomas

We have examined the character and carcinogenic properties of the normal-appearing epidermis overlying basal cell carcinomas by immunohistochemical methods, employing a series of monoclonal antibodies. The labelling index was significantly increased in the atrophic epidermis overlying basal cell carcinomas (solid type, n = 20), compared with the epidermis overlying or adjacent to squamous cell carcinoma (n = 20), keratoacanthoma (n = 10), dermatofibroma (n = 10), neurofibroma (n = 10), soft fibroma (n = 10), pyogenic granuloma (n = 10) and cutaneous leiomyoma (n = 5). Cells which expressed epidermal growth factor (EGF) receptor were detected in all layers of the epidermis over the basal cell carcinomas, but not the other tumours. Basement membrane-related antigens, including bullous pemphigoid antigen and GB3 antigen, were decreased in the epidermis. AE1, the monoclonal antibody against basal cell keratin, reacted with the uppermost layers of the normal-appearing epidermis overlying the basal cell carcinomas. ICAM-1 expression was very weak in the overlying epidermis. The dermis subjacent to the proliferating epidermis showed staining for transforming growth factor-alpha (TGF-alpha), strong positive PECAM-1 staining of endothelium, and numerous HLA-DR-positive cells. From these results, we suggest that the proliferative activity in the epidermis overlying basal cell carcinomas is not a state induced by the dermal infiltrate, but represents carcinogenic activity of the epidermis.