Prurigo pigmentosa

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.

Treatment of Confluent and Reticulated Papillomatosis with Azithromycin

Confluent and reticulated papillomatosis (CRP) is a relatively rare disorder of unknown origin, mostly affecting young female adults. We here present the case of a 21-year-old male patient with confluent and reticulated papillomatosis. Skin examination revealed brownish, verrucous, hyperkeratotic, 2 to 5 mm papules, which formed confluent patches and plaques with a reticulate network on the interscapular area. The patient was initially treated with ketoconazole cream for two weeks without improvement. The disease can be rather persistent and resistant to topical therapy. Our case showed a satisfactory response to treatment with azithromycin. Although this treatment is known to be effective in some cases, the action mechanism of azithromycin on CRP is not fully understood.

Prurigo pigmentosa: not an uncommon disease in the Turkish population

BACKGROUND

Prurigo pigmentosa (PP) is a rare inflammatory dermatosis of unknown etiology. It is characterized by erythematous papules of the trunk that resolve leaving a reticulate hyperpigmentation. The original report from Japan in 1971 was followed by new cases, mostly of Japanese origin.

METHODS

We scrutinized PP cases diagnosed in our clinic and reviewed the English, German, French, and Turkish language literature.

RESULTS

We report six additional Turkish patients. We found more than 40 cases reported from various countries outside Japan. The patients had different racial origins. The number of Turkish patients reported in recent years is higher than the number of other non-Japanese patients reported.

CONCLUSIONS

The disease is not uncommon in the Turkish population. It may be underestimated in other countries with Caucasian populations. Therapeutic results with tetracycline and doxycycline was successful in our patients.

Prurigo Pigmentosa Successfully Treated with Low-Dose Isotretinoin

BACKGROUND/AIMS

Prurigo pigmentosa (PP) is an uncommon inflammatory disease with pruritic reddish papules, papulovesicules or vesicules that are symmetrically localized on the trunk and nape, accompanied by reticular hyperpigmentation. Currently available therapeutic options seem somewhat unsatisfying. Herein, we report an 18-year-old female with PP successfully treated with low-dose isotretinoin.

METHODS

The patient presented with a symmetrical pruritic eruption on the lateral sides of her trunk with erythematous papules on a hyperpigmented background. Based on the typical clinical and associated histological findings, the patient was diagnosed as PP and a treatment with low-dose isotretinoin 0.3 mg/kg/day (20 mg/day) was started.

RESULTS

After a total of 3 months of 20 mg/day isotretinoin therapy, all erythematous macules and papules resolved and the residual pigmentation had almost disappeared.

CONCLUSION

Low-dose isotretinoin is not only adequate for the improvement of erythematous lesions, it also helps resolve the reticular hyperpigmentation of PP. Further studies are needed to observe the efficacy of isotretinoin in the treatment of PP.

[Prurigo pigmentosa]

Prurigo pigmentosa is an infrequent inflammatory dermatosis of unknown etiology, characterized by recurrent episodes of pruritic erythematous papules which develop into intense reticulated pigmentation. It has been referenced most frequently in young women in Japan. Only thirty cases have been described outside of Japan. We describe a 32-year-old Spanish female who developed a pruritic dermatosis with the clinical characteristics and histopathological findings of prurigo pigmentosa. We review the epidemiological, clinical and histopathological characteristics of this peculiar skin disease.

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.