Pityriasis rotunda: sporadic occurrence in an elderly Caucasian patient with diabetes mellitus

ARTICLE

Auteur(s) : Severino Persechino¹, Salvatore Raffa², Cristiano Caperchi¹, Vincenzo Visco², Emanuele Verga¹, Massimo Trappolini³, Maria Rosaria Torrisi^2,4

¹Unità Operativa di Dermatologia, Azienda Ospedaliera Sant’Andrea, Via di Grottarossa, 1035-1039, 00189 Roma, Italy
²Unità Operativa di Diagnostica Cellulare, Azienda Ospedaliera Sant’Andrea, Roma, Italy
³Unità Operativa di Medicina Interna, Azienda Ospedaliera Sant’Andrea, Roma, Italy
⁴Dipartimento di Medicina Sperimentale, “Sapienza” Università di Roma, Italy

Two different types of Pityriasis Rotunda (PR) have been previously reported [1]. Type 1, non-familial and associated with systemic diseases and/or malignancy, includes black or oriental patients with hyperpigmented lesions. Type 2 shows a strong familial tendency, no association with systemic diseases and includes Caucasian patients from the Mediterranean area, almost exclusively Sardinia [2, 3]. Recently, a case report of familial pityriasis rotunda in black-skinned patients has been described [4]. In both variants the lesions can resemble ichthyosis vulgaris; histologically, the characteristic finding is the association of hyperkeratosis with keratotic follicular plugs and a thin granular layer [2, 3, 5].

A 68-year-old diabetic man, born in Sardinia (Italy), affected by type 2 diabetes mellitus over the past 30 years with an inadequate control of glycemia levels and characterized by macroangiopathic complications and amputation of the left leg, presented asymptomatic scaly patches of eighteen months’ duration. Physical examination revealed five well-defined, circular, scaly, hyperkeratotic patches that varied from 2 to 2.5 cm in diameter, localized on the neck (two) and trunk (three) (figure 1). They were light brown and remained stable in size and location, even following corticosteroids or antifungal topical treatments. The lesions on the trunk showed an inflammatory appearance, probably related to the forced use of a wheelchair. Microscopical analysis and cultural tests performed to search for mycoses repeatedly resulted negative.

Histological study of a punch-biopsy specimen revealed a thinned granular layer, thickening of the corneal layer and a slight chronic lymphocytic infiltrate in perivascular and periadnexal areas of the mid and superficial dermis (figures 2A, B). Electron microscopy revealed hyperkeratosis with large keratotic follicular plugs (figures 2C, D). However, in contrast to ultrastructural findings of ichthyosis vulgaris and previous reports of PR [5, 6], no abnormalities in the shape, size and number of keratohyaline granules were found. This finding, typical of acquired ichthyosis, has also previously been reported in some patients with familial PR [1].

Two months after the diagnosis, the patient follow-up did not show significant modifications of the lesions, when the glycemia levels were normalized. However, three months after the PR diagnosis, vascular and metabolic complications of the disease resulted in the death of the patient.

In this case, an unusual onset of the disease was observed, considering that the patient was an elderly Sardinian man with no familiarity for pytiriasis rotunda or other genodermatoses. We suppose that the association with a chronic systemic disease, such as type 2 diabetes mellitus, with micro- and macrovascular complications, might have a role as an initiating effect in non-familial sporadic cases of pytiriasis rotunda.

Acknowledgements

References

2 Aste N, Pau M, Aste N, Biggio P. Pityriasis rotunda: a survey of 42 cases observed in Sardinia, Italy. Dermatology 1997; 194: 32-5.

3 Ena P, Cerimele D. Pityriasis rotunda in childhood. Pediatr Dermatol 2002; 19: 200-3.

4 Friedmann AC, Ameen M, Swale VJ. Familial pityriasis rotunda in black-skinned patients; a first report. Br J Dermatol 2007; 156: 1365-7.

5 Yoshida Y, Mitsuhashi Y, Kondo S, Ito Y. Pityriasis rotunda with low levels of steroid sulfatase. Eur J Dermatol 2007; 17: 248.

6 Hashimoto Y, Suga Y, Chikenji T, Matsuba S, Mizoguchi M, Kakuta M, Ogawa H. Immunohistological characterization of a Japanese case of pityriasis rotunda. Br J Dermatol 2003; 149: 196-8.