Concurrent pityriasis rotunda and acquired ichthyosis with IgG myeloma

Ichthyosis: etiology, diagnosis, and management

The ichthyoses are a heterogeneous group of disorders with both inherited and acquired forms. Clinical presentation, pattern of inheritance, and laboratory evaluation may establish a precise diagnosis, which can assist in prognosis and genetic counseling. Congenital autosomal recessive ichthyosis (CARI) usually presents at birth, often as a collodion baby. CARI can progress into any one of a spectrum of disorders. Lamellar ichthyosis is characterized by dark, plate (armor)-like scale. This disease is often caused by mutations in the gene encoding the enzyme transglutaminase 1. Congenital ichthyosiform erythroderma is another phenotype within CARI, marked by generalized redness and fine white scale. Epidermolytic hyperkeratosis is an autosomal dominant disorder characterized by hyperkeratosis and blistering, and at least six clinical phenotypes have been described. It may be due to mutations in the gene encoding the intermediate filament proteins keratin 1 and 10. Ichthyosis vulgaris is the most common ichthyosis, and is inherited in an autosomal dominant pattern. Involvement is generally mild and may vary greatly with climate and humidity. X-linked ichthyosis, due to a defect in the enzyme steroid sulfatase, affects males with generalized scaling that usually begins soon after birth. There may be associated corneal opacities that do not affect vision. Sjögren-Larsson syndrome is an autosomal recessive ichthyosis associated with progressive spastic paralysis and mental retardation. This condition is caused by mutations in the gene for fatty aldehyde dehydrogenase. Refsum's disease, due to accumulation of phytanic acid, results in ichthyosis and progressive neurologic dysfunction. The erythrokeratodermas are characterized by hyperkeratosis and localized erythema. Erythrokeratodermia variabilis is autosomal dominant and characterized by generalized or localized hyperkeratosis and migratory red patches. Mutations in the genes encoding the gap junction proteins, connexins, underlie this disorder. Netherton's syndrome is an autosomal recessive disorder characterized by ichthyosis, a hair shaft abnormality and atopy. The ichthyosis may present at birth with erythroderma or in some cases a collodion presentation. However, a frequent characteristic skin manifestation is ichthyosis linearis circumflexa. Netherton's syndrome has been found to be due to an abnormality in a serum protease inhibitor. Acquired ichthyosis can have a variety of underlying causes including neoplastic, infectious, drugs, endocrine, metabolic, autoimmune, malabsorptive states, and hereditary. Topical, and in more severe cases, systemic, therapy are useful in managing this array of disorders of cornification.

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.

Monoclonal gammopathies and associated skin disorders

The monoclonal gammopathies are characterized by clonal proliferation of plasma cells and other clonally related cells in the B-cell lineage. These disorders include monoclonal gammopathy of undetermined significance, multiple myeloma, Waldenström macroglobulinemia, heavy chain diseases, plasmacytoma, and primary amyloidosis. Many skin disorders have been described in association with monoclonal gammopathies. This article provides an introduction to the definition, detection, natural course, and spectrum of monoclonal gammopathies and a brief discussion of pathogenesis. The article also reviews the skin disorders associated with monoclonal gammopathies, categorizes the association, and evaluates the strength of the association.

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.