Abstract: Histiocytoses are rare diseases caused by the proliferation of histiocytes. The pathogenesis remains unknown and the highest incidence occurs in pediatric patients. The clinical presentations can be varied, in multiple organs and systems, and the skin lesions are not always present. Evolution is unpredictable and treatment depends on the extent and severity of the disease. It is described the case of a patient with various neurological symptoms, extensively investigated, who had its was diagnosed with histiocytosis from a single skin lesion. This report highlights the importance of Dermatology in assisting the investigation of difficult cases in medical practice.

A Calcifilaxia, também conhecida como arteriolopatia urêmica calcificante, é uma complicação freqüentemente observada nos pacientes com hiperparatireoidismo secundário à insuficiência renal crônica, ocorrendo principalmente em mulheres. Caracteriza-se por necrose isquêmica cutânea, de instalação aguda e progressiva, secundária à calcificação de vasos sanguíneos de pequeno ou de médio calibre. Trata-se de uma afecção rara e grave, cuja patogênese é obscura, e o melhor tratamento é a prevenção, especialmente visando manter os níveis adequados de cálcio e de fósforo. Descrevese um caso desta moléstia em paciente portadora de hiperparatireoidismo secundário à insuficiência renal crônica, submetida a tratamento clínico, desbridamento cirúrgico e enxertos autólogos de pele total, com resolução completa do quadro após 6 meses.

Calciphylaxis, also known as calcific uremic arteriolopathy, is a severe complication often observed in patients with hyperparathyroidism secondary to chronic renal failure, which occurs mainly in women. It is characterized by ischemic tissue loss secondary to progressive vascular compromise. This is a rare and severe condition and its pathogenesis is unclear. The best treatment is prevention, especially in order to maintain adequate levels of calcium and phosphorus. We describe a case of this disease in a patient with hyperparathyroidism secondary to chronic renal failure who underwent medical treatment, surgical debridement and total skin autografts, with resolution of symptoms after 6 months.