Pityriasis rotunda: two cases in black Americans

Pityriasis Rotunda: A Case Report of Familial Disease in an American-Born Black Patient

Pityriasis rotunda is an uncommon dermatosis with an unusual geographic and racial distribution. The skin disorder is characterized by sharply defined, perfectly circular, scaly patches with no inflammatory changes. Notably, it may be associated with underlying malignancy or chronic infection. We report an uncommon familial case in an American-born female.

Pityriasis rotunda diagnosed in Canada: case presentation and review of the literature

BACKGROUND

Pityriasis rotunda is a rare cutaneous disorder characterized by scaly, circular, well-demarcated, hypo- or hyperpigmented, fine plaques over the trunk and extremities.

OBJECTIVE

We present a case of pityriasis rotunda in a 44-year-old African-Canadian woman who presented to a community dermatology practice in Toronto.

RESULTS

Pityriasis rotunda has been well described in Japan, Italy, and South Africa. It is extremely rare in North America, with nine reported cases to date, the majority of which were diagnosed in the United States.

CONCLUSION

Pityriasis rotunda is a rare cutaneous disorder associated with systemic disease. To the best of our knowledge, this is the second report of pityriasis rotunda diagnosed in Canada.

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: 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.

Pityriasis rotunda in a Caucasian woman from the Mediterranean area

Pityriasis rotunda (PR) has been known to affect, almost exclusively, Japanese and South African Bantu, often in association with various systemic diseases. However, the occurrence of PR in Caucasian patients is extremely rare, and has been previously described in only three reports. We hereby report a case of an apparently healthy Caucasian woman from Israel having clinical and histological features characteristic of PR. Pityriasis rotunda (PR) is a rare disorder of keratinization characterized by strikingly well demarcated, perfectly round scaly brownish patches of variable number and diameter located mainly on the trunk and extremities. The exact place of this disorder within the nosology of the cutaneous dermatoses is not yet fully established. However, most authors regard it as a special circumscribed form of acquired ichthyosis with a histological resemblance to ichthyosis vulgaris. For more than half a century following the first description of this disorder in 1906 cases reported were almost exclusively from the Far East, particularly from Japan, or in South African Negroids, with a few cases of West Indian Negroids, usually in association with various debilitating diseases. The first report of a Caucasian patient appeared in the literature in 1966 and since then there have been only two additional reports of PR in Caucasian patients.

Pityriasis rotunda as a cutaneous marker of hepatocellular carcinoma: a comparison with its prevalence in other diseases

In an attempt to substantiate the claim that pityriasis rotunda may be a useful cutaneous marker of hepatocellular carcinoma in South African Blacks, the prevalence of the rash in 63 unselected South African Blacks with this tumour was compared to that in 63 matched patients with active tuberculosis, 63 with other malignant tumours, and 63 with various forms of chronic benign hepatic disease. The prevalence of pityriasis rotunda in hepatocellular carcinoma was 15.9%, which was appreciably greater (P = 0.0005) than the overall prevalence of the rash (2.6%) in the controls. The prevalence was 4.8% for tuberculosis (P = 0.038), 0% for other malignant diseases (P = 0.0007), and 3.2% for chronic benign hepatic disease (P = 0.015). We conclude that the presence of pityriasis rotunda is a useful pointer to the diagnosis of hepatocellular carcinoma in South African Blacks.