Cutaneous tuberculosis (CTB) is the result of a chronic infection by Mycobacterium tuberculosis, M. ovis and occasionally by the Calmette-Guerin bacillus. The clinical manifestations are variable and depend on the interaction of several factors including the site of infection and the host's immunity. This article revises the current knowledge about this disease's physiopathology and immunology as well as detailing the possible clinical presentations.

The evolution in the knowledge of tuberculosis' physiopathology allowed not only a better understanding of the immunological factors involved in the disease process, but also the development of new laboratory tests, as well as the establishment of a histological classification that reflects the host's ability to contain the infectious agent. At the same time, the increasing bacilli resistance led to alterations in the basic tuberculosis treatment scheme in 2009. This article critically examines laboratory and histological investigations, treatment regimens for tuberculosis and possible adverse reactions to the most frequently used drugs.

Resumo: A psoríase é doença crônica que afeta a pele e, eventualmente, as articulações. A terapia biológi-ca age bloqueando citocinas inflamatórias implicadas na patogênese da doença, dentre elas o fator de necrose tumoral alfa. Este também tem papel na defesa do hospedeiro contra o Mycobacterium tuberculosis. Relata-se um caso de psoríase com boa resposta ao infliximabe, porém com desenvolvimento de tuberculose esplênica durante o tratamento. Palavras-chave: Psoríase; Terapia biológica; Tuberculose Abstract: Psoriasis is a chronic inflammatory disease affecting the skin and occasionally the joints. The biological agents have been engineered to target a specific step in the inflammatory cascade that leads to psoriasis, including tumor necrosis factor, which has a central role in the host defense against Mycobacterium tuberculosis. This is a case report about a psoriatic patient who presented splenic tuberculosis during treatment with infliximab. Keywords: Psoriasis; Biological therapy; Tuberculosis CASO CLÍNICO INTRODUÇÃOA psoríase é doença crônica de curso intermitente que afeta a pele e, em alguns casos, as articulações. A gravidade da doença é bastante variável, sendo que em suas formas mais graves há grande comprometimento da qualidade de vida dos pacientes. Até o momento não há cura definitiva para a psoríase, sendo objetivos do tratamento o rápido controle da doença e a remissão prolongada.Formas leves podem ser tratadas com agentes tópicos, enquanto formas moderadas e graves geralmente necessitam de fototerapia ou tratamento sistê-mico, incluindo medicações como metotrexato, acitretina, ciclosporina ou agentes biológicos.