Abstract Local anesthetics are essential medications for the conduction of dermatological procedures. They stop the depolarization of nerve fibers and are divided into two main categories, the amide and ester types. Systemic toxicity with reflex on the central nervous and cardiovascular systems is their most feared adverse reactions, and the anaphylactic reaction is the most concerning one. Although potentially fatal, these events are extremely rare, so local anesthetics are considered safe for use in in-office procedures.

A sixty-one year old white female was referred to the Dermatology Department to treat an ingrown nail in the inner corner of the left hallux. Examination of the entire nail unit showed the presence of xanthonychia in the outer corner besides thickening and increase in the transverse curvature of the nail plate. Dermoscopy and nuclear magnetic resonance of the free edge of the nail plate detected characteristic signs of onychomatricoma, a diagnosis that was later confirmed by anatomopathological exam.

Paciente de 80 anos, branco, sexo masculino, encaminhado para avaliação de nódulo eritematoso de 2 cm, assintomático, de crescimento rápido, localizado na região malar esquerda, com quatro meses de evolução. À dermatoscopia visualizou-se fundo homogêneo róseo com telangiectasias polimorfas. O exame anatomopatológico revelou massas tumorais atingindo a derme profunda e o subcutâneo, compostas por células arredondadas, de citoplasma escasso. A imunohistoquímica foi positiva para CK20, confirmando o diagnóstico de carcinoma de células de Merkel.

An 80-year-old Caucasian male patient was referred for evaluation of a rapidly growing, asymptomatic, erythematous nodule measuring 2 cm in diameter on his left cheek. The lesion had been present for four months. Dermoscopy revealed a homogeneous pink background with polymorphous telangiectatic vessels. Histopathology showed tumors in the deep dermis and subcutis composed of round cells with scant cytoplasm. Immunohistochemical staining was positive for CK20 confirming the diagnosis of Merkel cell carcinoma.