Fish Tank Granuloma Caused byMycobacterium marinumin Two Aquarists: Two Case Reports

Abstract

Mycobacterium marinum, the cause of chronic systemic infections in fish, occasionally causes granulomatous skin and soft tissue lesions in humans. Cutaneous mycobacterial infection in two patients owing to unusual circumstances is presented in this report. The first patient was infected through improper hygienic behavior, while infection in the second patient was previously misdiagnosed as rheumatoid arthritis and treated with methylprednisolone for a period of three months, which resulted in a rare systemic spread of M. marinum into the bones of the hand, testis, and epididymis. Simultaneously, screening for possible sources of M. marinum infection in patients' aquaria revealed positive fish harboring VNTR profiles identical to those obtained for clinical isolates from patients.

Detection of Mycobacterium marinum in clinically asymptomatic Siamese fighting fish (Betta splendens) from ornamental fish shops in Chiang Mai Province, Thailand

“…may play a role as an NTM infection source for risk groups, such as fishery professionals or ornamental fish hobbyists. Exposure to contaminated water and superficial cuts or abrasions of the skin are two major risk factors of M. marinum infection in nonimmunocompromised patients [22,23]. Ornamental fish owners and others with high risk of M. marinum infection should be educated about the zoonotic risk associated with handling aquarium fish and the aquarium environment, including how to protect themselves from infection.…”

Clinical Implications for the Timely Diagnosis of Mycobacterium marinum in the Age of Biologic Therapy: A Case Report and Review of the Literature

“…A review of the literature discovered other cases that were mistakenly treated as RA [8, 9] or were presumed to be refractory disease in patients on immune suppressant medications for inflammatory disorders [10–12]. Although persistent infection with NTM is relatively rare in immunocompetent hosts, the increasing use of immunosuppressive therapy has seen increased incidence of these diseases [13].…”

Mycobacterium marinum infection: a case report

“…The infection by Mycobacterium marinum in humans – also known as aquarium granuloma, swimming pool granuloma or fish tank granuloma [1] – is an uncommon disease that mainly affects the skin, usually with a chronic, indolent and benign evolution [1]. The manifestations include granulomatous lesions, predominantly with acral distribution, that affect patients regardless of their immune status.…”

“…The manifestations include granulomatous lesions, predominantly with acral distribution, that affect patients regardless of their immune status. The clinical and histopathological findings are non-specific, represented by papules, nodules or erythematous plaques, and by the presence of tuberculous granulomas with unusual evidence of bacilli on examination [1-3]. Due o diagnostic difficulties, ranging from the infrequent distribution, and the plurality of clinical presentations, the Mycobacterium marinum can cause from erythematous to plate-shaped, papules, nodules, single or multiple ulcerations and even sporotrichosis-like presentations, differential diagnosis with other granulomatous lesions is essential [4].…”

“…Common antibiotics are usually effective [1,5]. Herein, we report the case of an immunocompetent patient who had a chronic undiagnosed injury for at least five years, on the fifth finger of the right hand, whose careful investigation of history of exposure allowed the correct etiologic identification of M. marinum , and therefore the institution of proper treatment.…”