Difficulties in the diagnosis of fish tank granuloma: Case report
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Department of Dermatology, Sexually Transmitted Diseases and Clinical Immunology, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, Poland
Submission date: 2020-04-30
Final revision date: 2020-08-31
Acceptance date: 2020-08-31
Online publication date: 2020-11-06
Corresponding author
Ewelina Woźniak   

Department of Dermatology, Sexually Transmitted Diseases and Clinical Immunology, School of Medicine, Collegium Medicum, University of Warmia and Mazury Al. Wojska Polskiego 30 10-229 Olsztyn, Poland. Tel.: +4889 678 66 70, fax +4889 678 66 41.
Pol. Ann. Med. 2020;27(2):200-204
Fish tank granuloma is a rare dermatitis caused by Mycobacterium marinum. Infection occurs through contact of damaged skin with water or aquatic animals infected with these bacteria.

It is likely that skin infection caused by M. marinum transmitted from Clarias gariepinus has as yet not been reported in literature. Our case report is presumably the first publication. Dermatoscopy as a useful method in the diagnosis of skin infections caused by atypical mycobacteria. Our article presents new dermatoscopic features of fish tank granuloma.

Case study:
The case report applies to a 30-year old, white, Caucasian man referred because of a single, well-demarcated plaque measuring 2 × 4 cm, localized on third finger on left hand above proximal phalanx, without subjective symptoms. The diagnosis was confirmed by medical history, dermoscopy and histopathological examination. Patient was successfully treated with sulfamethoxazole and trimethoprim.

Results and discussion:
Due to the fact that M. marinum infection is uncommon, in case of clinical suspicion it is necessary to perform skin biopsy, culture and tissue PCR analysis. Knowledge about the opportunities and limitations of theses laboratory tests is pivotal to reasonable clinical decision-making.

Dermoscopy is useful to make a diagnosis, but there are still too few accounts in literature. The correct diagnosis determines the effective treatment.

None declared.
None declared.
Iredell J, Whitby M, Blacklock Z. Mycobacterium marinum infection: epidemiology and presentation in Queensland 1971–1990. Med J Aust. 1992;157(9):596–598.
Aubry A, Chosidow O, Caumes E, Robert J, Cambau E. Sixty-three cases of Mycobacterium marinum infection: Clinical features, treatment, and antibiotic susceptibility of causative isolates. Arch Intern Med. 2002;162(15):1746–1752.
Bartralot R, Garcia-Patos V, Sitjas D, et al. Clinical patterns of cutaneous nontuberculous mycobacterial infections. Br J Dermatol. 2005;152(4):727–734.
Bhatty MA, Turner DPJ, Chamberlain ST. Mycobacterium marinum hand infection: Case reports and review of literature. Br J Plast Surg. 2000;53(2):161–165.
Rallis E, Koumantaki-Mathioudaki E. Treatment of Mycobacterium marinum cutaneous infections. Expert Opin Pharmacother. 2007;8(17):2965–2978.
Johnson MG, Stout JE. Twenty-eight cases of Mycobacterium marinum infection: retrospective case series and literature review. Infection. 2015;43(6):655–662.
Petrini B. Mycobacterium marinum: Ubiquitous agent of waterborne granulomatous skin infections. Eur J Clin Microbiol Infect Dis. 2006;25(10):609–613.
Barker LP, George KM, Falkow S, Small PL. Differential trafficking of live and dead Mycobacterium marinum organisms in macrophages. Infect Immun. 1997;65(4):1497–1504.
Aubry A, Mougari F, Reibel F, Cambau E. Mycobacterium marinum. Microbiol. Spectr. 2017;5(2).
Travis WD, Travis LB, Roberts GD, Su DW, Weiland LW. The histopathologic spectrum in Mycobacterium marinum infection. Arch Pathol Lab Med. 1985;109(12):1109–1113.
Conforti C, Zalaudek I, Vichi S, Di Meo N. Dermoscopy of Mycobacterium marinum skin infection: A challenging diagnosis. Acta Dermatovenerol Croat. 2019;27(4):278–279.
Errichetti E, Stinco G. Dermoscopy in general dermatology: A practical overview. Dermatol Ther (Heidelb). 2016;6(4):471–507.
Hashish E, Merwad A, Elgaml S, et al. Mycobacterium marinum infection in fish and man: Epidemiology, pathophysiology and management; A review. Vet Q. 2018;38(1):35–46.
Koushk-Jalali B, Freitag AP, Tigges C, Oellig F, Hillemann D, Kreuter A. Sporotrichoid fish tank granuloma. QJM. 2019;112(2):147–147.
Parrish N, Luethke R, Dionne K, Carroll K, Riedel S. Case of Mycobacterium marinum infection with unusual patterns of susceptibility to commonly used antibiotics. J Clin Microbiol. 2011;49(5):2056–2058.
Jacobs S, George A, Papanicolaou GA, et al. Disseminated Mycobacterium marinum infection in a hematopoietic stem cell transplant recipient. Transpl Infect Dis. 2012;14(4):410–414.
Errichetti E, Stinco G. Dermatoscopy of Granulomatous disorders. Dermatol Clin. 2018;36(4):369–375.
Błaszczyk M. Cutaneous sarcoidosis: Clinical presentation and diagnostic difficulties. Przegl Dermatol. 2012;99(3):185–194 [in Polish].
Nolte O, Haag H, Häfner B. A mutation in the 65,000 Dalton heat shock protein gene, commonly used for molecular identification of non-tuberculous mycobacteria, leads to the misidentification of Mycobacterium malmoense as Mycobacterium marinum. Mol Cell Probes. 2005;19(4):275–277.
Ho M, Ho C, Chong L. Atypical mycobacterial cutaneous infections in Hong Kong: 10-year retrospective study. Hong Kong Med J. 2006;12(1):21–26.
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