Cutaneous Nocardiosis Simulating Cutaneous Lymphatic Sporotrichosis

Abstract

Sporotrichosis is the subcutaneous mycosis caused by several species of the Sporothrix genus. With worldwide occurrence, the State of Rio de Janeiro is presently undergoing a zoonotic sporotrichosis epidemic. The form of lymphocutaneous nocardiosis is rare, being caused especially by Nocardia brasiliensis. It appears as a nodular or ulcerated lesion, with multiple painful erythematous nodules or satellite pustules distributed along the lymphatic tract, similar to the lymphocutaneous variant of sporotrichosis. We present a 61-year-old man who, after an insect bite in the left leg, developed an ulcerated lesion associated with ascending lymphangitis, nonresponsive to previous antibiotic therapies. The patient was admitted for investigation, based on the main diagnostic hypothesis of lymphatic cutaneous sporotrichosis entailed by the highly suggestive morphology, associated with the epidemiologic information that he is a resident of the city of Rio de Janeiro. While culture results were being awaited, the patient was medicated with sulfamethoxazole-trimethoprim to cover CA-MRSA and evolved with total healing of the lesions. After hospital discharge, using an ulcer fragment, an Actinomyces sp. was cultivated and N. brasiliensis was identified by molecular biology. The objective of this report is to demonstrate a case of lymphocutaneous nocardiosis caused by N. brasiliensis after a probable insect bite. Despite the patient being a resident of the State of Rio de Janeiro (endemic region for sporotrichosis), it is highlighted that it is necessary to be aware of the differential diagnoses of an ulcerated lesion with lymphangitis, favoring an early diagnosis and appropriate treatment of the illness.

Lymphocutaneous nocardiosis caused by Nocardia brasiliensis in an immunocompetent patient: a case report

“…Another transmission route is through infected animals. 5,7,8 So far, there have been only two cases reported in China of lymphocutaneous nocardiosis caused by N. brasiliensis in immunocompetent patients. One was reported by Chu et al 10 in 2017 and occurred in an 87-year-old woman following a wasp sting.…”

First Case of Nocardia pseudobrasiliensis Causing Primary Cutaneous Nocardiosis in an Immunocompetent Patient

“…7 Nocardia species are gram-positive, rod-shaped bacteria, which are partially acid-fast beaded branching filaments that grow under aerobic conditions. 10 N brasiliensis and N pseudobrasiliensis can be distinguished from the other species by adenine hydrolysis and nitrate reductases, but these tests are not commonly available in most microbiology laboratories. Therefore, matrix-assisted laser desorption ionization-time of flight mass spectroscopy and gene sequence analysis are used for species identification as was seen in our case.…”

“…Immunocompetent patient with cutaneous nocardiosis should be ideally treated with trimethoprim-sulfamethoxazole for 2 to 4 months, which may need to be extended further for some immunocompromised patients to prevent recurrence. 10…”

A case report and review of lymphocutaneous nocardiosis caused by Nocardia brasiliensis reported in China

“…The present authors' patient formed the lesion from the insect bite. So far, there are only four cases in the world of primary cutaneous nocardiosis caused by N. brasiliensis induced by insect bites (Chu et al, 2017;O'Connor & Dire, 1992;Paredes et al, 1999;Secchin et al, 2017). In china, Chu et al (2017) reported an 87-year-old female patient who presented painful erythema on her right forearm following a wasp sting, and rapidly deteriorated.…”

“…Both Gram staining and Anti-acid staining showed positive branching bacterium (Figure 1d is not common to primary cutaneous nocardia infection in immunecompetent host. N. brasiliensis is the most common species that causes skin infection especially in lymphocutaneous nocardiosis type (Ayoade, Mada, Joel Chandranesan, & Alam, 2018;Secchin et al, 2017;Wilson, 2012). Lymphocutaneous nocardiosis, also called lymphocutaneous type, may resemble sporotrichosis clinically and easy to misdiagnose (Ayoade et al, 2018;Bryant, Davis, Kucenic, & Mark, 2010;Secchin et al, 2017).…”