Familial pityriasis rotunda

Pityriasis in dermatology: an updated review

Dermatology has a very distinctive lexicon. The term pityriasis refers to several dermatologic conditions which all feature scaling of the skin. According to the Merriam-Webster dictionary, the term pityriasis was first used in print in 1684. Although the diseases beginning with the name pityriasis are of diverse causation, they do represent important dermatologic diseases, with some common and others quite rare. It is important for dermatologists to be aware and updated on all pityriasis conditions in dermatology.

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.

Cutaneous paraneoplastic syndromes in solid tumors

OBJECTIVE

To provide an overview of the clinical manifestations, pathophysiology, and oncologic implications of the cutaneous paraneoplastic syndromes that occur predominantly in patients with solid tumors.

METHODS

A review was performed of the literature identified by a comprehensive MEDLINE search.

RESULTS

Diverse cutaneous paraneoplastic syndromes may be associated with underlying tumors. They include musculoskeletal disorders (clubbing, hypertrophic osteoarthropathy, dermatomyositis, and multicentric reticulohistiocytosis), reactive erythemas (erythema gyratum repens and necrolytic migratory erythema), vascular dermatoses (Trousseau's syndrome), papulosquamous disorders (acanthosis nigricans, tripe palms, palmar hyperkeratosis, acquired ichthyosis, pityriasis rotunda, Bazex's syndrome, florid cutaneous papillomatosis, the sign of Leser-Trélat, and extramammary Paget's disease), and disorders of hair growth (hypertrichosis lanuginosa acquisita). The clinical manifestations of these dermatoses may precede, coincide with, or follow the diagnosis of cancer. The presence of a cutaneous paraneoplastic syndrome is often associated with a poor prognosis.

CONCLUSIONS

Cutaneous paraneoplastic syndromes are specific constellations of mucous membrane and/or skin abnormalities that are caused by an underlying tumor. Since they may be the presenting sign of an occult cancer, cognizance of their features and clinical implications are of considerable importance. Individuals with these syndromes should have a thorough workup for an associated malignancy.

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.

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.