Norwegian scabies in a patient with Sézary Syndrome

case report.

Abstract

Crusted scabies is a rare form of infestation of the octopod Sarcoptes scabiei var. hominis, characterized by the large number of parasites. It mainly occurs in patients with immune system deficits,
such as T-cell lymphoma, leprosy, acquired immunodeficiency syndrome, graft versus host disease, and use of immunosuppressants. The manifestations are thick, scaly, grayish crusts that extend beyond the circle of Hebra in the palmoplantar, subungual, and scalp regions. Dermoscopy has high sensitivity for identifying parasitosis. A variety of diseases make a differential diagnosis with crusted scabies, such as psoriasis, genodermatoses, seborrheic dermatitis, Darier disease, and Sézary syndrome, which must be excluded. This study aims to report a case of an older patient with a history of Sézary syndrome evolving into erythroderma that was associated with disseminated crusty and pruritic lesions and a suspected recurrence of the disease for whom diagnosis involved a dermatoscope, an accessible, cheap, and highly sensitive tool. This study used descriptive, observational, and cross-sectional research (case report) as its methodology. This report focused on the
dermoscopic findings, the excavated grooves, and delta-wing triangles, corresponding to the parasite, which are extremely relevant to diagnose crusted scabies. The reported clinical case is challenging due to the diagnostic difficulty as the Sézary syndrome with erythroderma and intense pruritus as uncommon manifestations, showing the importance of dermoscopic findings to
elucidate diagnoses. Immunosuppression favored the emergence of crusted scabies and that dermoscopy offers an excellent diagnostic tool.