Abstract We present the case of an HIV-negative man with asymptomatic penile erythematoviolaceous papules associated with similar slightly verrucous papules in the interdigital space of the right foot. A biopsy of the penile lesion confirmed Kaposi's sarcoma. No other causes of immunosuppression were observed. Penile lesions of KS are rare in HIV-negative individuals but it should also be considered in the differential diagnosis. Careful follow-up is recommended.

Abstract: BACKGROUND: Psoriasis is a chronic and prevalent disease, and the associated pruritus is a common, difficult-to-control symptom. The mediators involved in psoriatic pruritus have not been fully established. OBJECTIVE: To evaluate associations between the number of mast cells in psoriatic lesions and the intensity of pruritus. METHODS: 29 patients with plaque psoriasis were recruited. In all participants, Psoriasis Area and Severity Index and Body Surface Area were assessed. A questionnaire was administered to obtain clinical information and the Dermatology Life Quality Index. Pruritus was assessed using a visual analog scale and skin biopsies were performed for staining with Giemsa and Immunohistochemistry with C-Kit. RESULTS: Pruritus was observed in 91.3% of our patients. Median VAS was 6 (p25-75: 2-8). The immunohistochemical method revealed a mean of 11.32 mast cells/field and Giemsa staining revealed a mean of 6.72 mast cells/field. There was no correlation between the intensity of pruritus and mast cell count, neither in Immunohistochemistry (p = 0.15; rho = -0.27) nor in Giemsa (p = 0.16; rho = -0.27). Pruritus did not impact on the Dermatology Life Quality Index (p = 0.51; rho = -0.13). STUDY LIMITATIONS: The small sample size may be considered the main limitation of our study. CONCLUSIONS: Although mast cells are mediators of pruritus in many cutaneous diseases, our findings support that psoriatic pruritus is a complex disorder with multifactorial, complex pathophysiology, involving pruritogenic mediators others than mast cells.

The Osler-Weber-Rendu syndrome or Hereditary Hemorrhagic Telangiectasia (HHT) is a systemic fibrovascular dysplasia characterized by defects in the elastic and vascular walls of blood vessels, making them varicose and prone to disruptions. Lesions occur in different organs and can lead to hemorrhage in the lungs, digestive tract and brain. We describe the case of a patient with cutaneous manifestations and severe impairment of the digestive tract. It is important for the dermatologist to recognize this syndrome, since the cutaneous lesions may play a key role in diagnosis.