Pityriasis rotunda in childhood.

Pityriasis rotunda is a rare disease characterized by round or oval patches, localized mainly on the trunk, arms, and legs. The patches are usually lighter than the surrounding skin, but sometimes may be darker, and are covered by fine, adherent scales. Two types of pityriasis rotunda have been described. Type I has been observed mainly in oriental and black patients older than 60 years of age, and is often associated with systemic disease or malignancy. Type II has been observed in white patients younger than 40 years of age, is often familial, and has never been observed in association with malignancy or internal disease. On Sardinia, a cluster of patients with type II pityriasis rotunda has been described. From 1981 until 1998, 51 cases of this disease have been observed in the Department of Dermatology, University of Sassari; 32 of them were children. The great prevalence of pityriasis rotunda on Sardinia, an island which until 40 years ago had limited contact with the Italian mainland, and the presence of a large number of familial cases suggest that type II pityriasis rotunda should be considered a genetically determined disease. The trend toward spontaneous resolution after the age of 20 years suggests that pityriasis rotunda should be considered a genodermatosis with a temporary phenotypic expression.

Pityriasis rotunda mimicking tinea cruris/corporis and erythrasma in an Indian patient.

Pityriasis rotunda is a rare disease characterized by perfectly round to oval, sharply defined, scaly, hypo/hyperpigmented patches of variable number and size located mainly over the trunk and proximal extremities. More than 95% of the reported cases in medical literature are from three countries/ethnic populations, namely Japan, South Africa (Bantu), and Italy (Sardinian islanders). To the best of my knowledge, no patient with the characteristic clinico-pathologic features has been reported from the Indian subcontinent. I report a 44-year-old man with eighteen pityriasis rotunda patches, persistent for nearly 20 years. The lesions in the groin and axillae closely resembled erythrasma and tinea, and he had received treatment for these conditions several times in the past. Histopathology of the skin biopsy showed thinning of the epidermis with a thinned-out granular layer and a sparse lymphomononuclear infiltrate in the dermis. A review of literature suggests that there are two subsets of the disease. The type I subset is comprised of pityriasis rotunda associated with systemic illness and is seen in Black or Oriental patients with no family history of the disease. The lesions tend to subside on treatment of the underlying illness. The type II subset patients are Caucasians as well as Blacks and Orientals with no underlying systemic illness. Familial occurrence is possible; lesions tend to be persistent and unresponsive to therapy.

Pityriasis rotunda: a survey of 42 cases observed in Sardinia, Italy.

BACKGROUND: Pityriasis rotunda (PR) is an uncommon dermatosis characterized by multiple, round or oval, sharply demarcated scaling patches that are dyschromic and asymptomatic. It has been described in Japanese and in blacks, usually in association with certain infective or malignant systemic diseases. OBJECTIVE: The aim of this study is to further clarify this rare entity which in Italy seems to be confined to the island of Sardinia. METHODS: We studied 42 Sardinian patients, 22 males and 20 females, in an age range of 3-32 years. In 29 cases, the disease involved more than one family member. The patients were observed in Cagliari, the capital city of Sardinia. RESULTS: Bacterial, viral and fungal investigation yielded negative results. Haematochemical and immunological examination and thyroid, hypophyseal and adrenal hormones did not reveal any alterations. No systemic pathologies were found associated with the disease. CONCLUSIONS: The cases studied by us and those previously reported seem to indicate the presence of two distinct types of PR with significant prognostic differences.

Pityriasis rotunda: report of a familial occurrence and review of the literature.

Pityriasis rotunda is an uncommon dermatosis characterized by multiple, widely distributed, strikingly circular hypopigmented or hyperpigmented patches that are slightly scaly. It has been described in Oriental and black patients, usually in association with certain infective or malignant systemic diseases. Pityriasis rotunda is rare in white patients and does not act as a marker of malignancy. Our ultrastructural and histologic findings demonstrated that pityriasis rotunda is more closely related to congenital ichthyoses than ichthyosis vulgaris, contrary to previous reports. On the basis of our studies and a review of the literature, it seems that two types of pityriasis rotunda exist with significant prognostic differences.

Familial pityriasis rotunda.

Pityriasis rotunda is a rare dermatosis characterized by circular, dusty scaling, dyschromic patches, quite asymptomatic and mostly described in Japanese and blacks. The authors have seen three cases of pityriasis rotunda in a Sardinian family that are to be added to two other similar reports. The patients were all in good health. An interesting feature was the association with favism. On inquiry it was discovered that many more members of the family were affected by either or both pathologies. The authors believe this condition to be a form of minor acquired ichthyosis of which Sardinia could be an ethnic center.

Pityriasis rotunda: two cases in black Americans.

Pityriasis rotunda is an uncommon cutaneous disorder consisting of asymptomatic, perfectly circular, scaling plaques on the trunk and extremities. Histopathologic findings are consistent with ichthyosis vulgaris. The majority of cases are seen in association with an underlying disease, and most authors believe that this entity represents a form of acquired ichthyosis. Previous cases have been restricted to certain geographic and ethnic groups (most commonly Japanese and South African Bantu). We report two cases of pithyriasis rotunda, both occurring in black Americans. We believe that these are the first reported cases seen in Americans.

[Pityriasis lichenoides in a sibling pair]. / Pityriasis lichenoides bei einem Geschwisterpaar.

Two brothers are reported, who had pityriasis lichenoides within an interval of eighteen months. The hitherto unknown etiology of this dermatosis is discussed.

Relationship of pityriasis amiantacea to psoriasis. A follow-up study.

46 patients with pityriasis aminantacea have been reexamined with regard to the later development of psoriasis and atopic diseases, and their occurrence in first and second degree relatives. HLA antigens of the A, B and C series were also determined. Earlier suggestions of a close association with psoriasis were not confirmed. An association with atopic diseases could not be established. Occurrence of seborrheic dermatitis seems, however, common in patients with pityriasis amiantacea.