Pityriasis Rotunda

Abstract

A 13‐year‐old boy and his sisters (11 and 14, respectively] consulted us for the same derniatoses. The boy and the elder sister had been suffering for over 4 years, while the younger sister was in her first year of the disease. The clinical pictures were alike: many circular or oval patches of furfuraceous desquamation scattered over the trunk and limbs. Lesions were sharply demarcated and frequently confluent with a polycyclic outline (Figs. 1, 2). Their size varied from 2–3 cm to more than 10 cm and they numbered more than 40 in every patient. The patches were hypochromic and prominent over the sunbathed skin (Fig. 1); the boy alone bad a few lesions darker than the surrounding skin. The dermnloses appeared to fluctuate in severity with a modest improvement during summer, While its extension remained unchanged, a follow up after a year revealed that single lesions had eilber disappeared or spread out while new ones had surfaced; furthermore, the boy had no more hyperchromic lesions. The skin elsewhere was normal. We examined the parents and were surprised to learn that their father suffered from ichtbyosis vulgaris (IV) (Fig. 3); in addition, he stated that his mother had the same disease; he could not specify if other members of the family had any signs of IV or PR. Microscopic examinations and cultures were carried out in the children and were repeatedly negative for fungi. A bistologic examination was obtained from the father and his son. Both IV and PR sbowed the same picture: a moderate byperkeratosis (strictly ortokeratotic) surmounted an absent or reduced granular layer and an otherwise normal epidermis.

Familial pityriasis rotunda in black-skinned patients; a first report

“…The most recent report of familial pityriasis rotunda describes an affected Israeli brother and sister and their father. In this case and an earlier Sardinian case, the fathers had ichthyosis vulgaris 12,14 …”

“…In most of these cases the disease tended to affect father and child or siblings but the pattern of inheritance could not be established. There have been a few other cases of familial pityriasis rotunda reported, mostly in Italians 7,10,12–14 . In the family reported by Alberti et al ., 13 all affected individuals had the HLA‐A32 B40 Cw1 and DR2 haplotype.…”

Case Report. Pityriasis versicolor mimicking Pityriasis rotunda

“…Indeed, the first reports of PR in Italy, starting from 1986, exclusively concerned patients native of, and living in, Sardinia [6]. Subsequently, separate cases were reported in other areas of Italy, but they all concerned individuals from Sardinia, who had moved to other Italian regions [7, 11]. Therefore, in Italy, PR seems to have a peculiar ethnic incidence, since all the cases reported in the literature exclusively concern individuals belonging to the Sardinian population [9, 10].…”

“…The histologic pattern is that of ichthyosis vulgaris. This disease, initially reported in the Japanese population and also in black people in South Africa and the West Indies, was later described in Italy in subjects native of Sardinia, a major island in the Mediterranean [4–8]. The etiology of this disease is as yet unknown.…”

Pityriasis Rotunda in Childhood

“…In 1981 a white boy affected by pityriasis rotunda was observed on Sardinia, and since then more than 100 instances of the disease have been observed in children from Sardinia or of Sardinian descent (5–7). Forty‐two cases were reported by Aste et al (8) in the Department of Dermatology, University of Cagliari in 1997 and 47 cases were reported by Ena et al (9) in the Department of Dermatology, University of Sassari in 1998.…”