Not All Granulomas Come from Fish Tanks: A Chronic Non- Healing Hand Wound After Swimming Namisha Thapa1, DO; Luke Strnad2,3, MD 1 Department of Medicine, 2 Division of Infectious Disease, Oregon Health & Science University, 3 Epidemiology Programs, OHSU-Portland State University School of Public Health

Learning Objective

Understand the complexity of diagnosis and treatment of Mycobacterium marinum infection

Introduction Case Presentation “Aquarium granuloma”, “swimming pool granuloma”, A 27-year-old man presented with 2-year history of or “fish-tank granuloma” is caused by the non- non-healing left fifth digit hand wound. It initially tuberculous mycobacterium (NTM), M. marinum. started as erythema with fluctuance that began Usually chronic, indolent, non-healing wound, it after a cut from broken glass and subsequently requires meticulous history gathering, high clinical worsened after swimming in a river. suspicion, and often skin biopsy to make the diagnosis.

Clinical Timeline

3/2016 10/2016 12/2016 3/2017 4/2017 6/2017 8/2017 5/2018 10/201810/2018 Dermatology Third I&D. OHSU ED visit. Cut L small Exploratory Dermatology ID follow-up. ED visit for Telephone visit. Punch Culture showed Seen by plastic finger with surgery done follow-up. Some medication hand wound; encounter: no biopsy done, pan-sensitive surgery for broken glass. for possible Suspected non-adherence. I&D done. symptom negative AFB M. marinum punch biopsy. Swam in foreign object.* foreign body Improved wound, Discharged improvement, stain and (1/2). Started 6- AFB positive. Georgia river Wound and referred not open. Plan to home on 1 wk persistent culture. wks Doxycycline, ID started one week culture to surgery f/u in 2 months to of antibiotics pain/drainage Treated with but patient Doxycycline, later negative for determine therapy hydrocortisone stopped early due Ethambutol, AFB duration *pathology: squamous epithelium and granulation tissue with for dermatitis to improvement Bactrim extensive acute and chronic inflammation with areas of necrosis

May 2018 Physical Exam May 2018 Labs & Imaging Discussion: M. marinum

 Normal CBC, CMP, and CRP  Prefers cooler temperature both in vivo and vitro,  Wound culture: + M. marinum thus prefers extremities. It is difficult to culture  Hand MRI: soft tissue wound with depending on lab’s incubation temperature. underlying cellulitis without evidence of  Diagnosis sometimes made with granulomas on path abscess, osteomyelitis or septic arthritis  Though NTM (non-tuberculous mycobacterium), can have false positive QuantiFERON  Good cure rate with appropriate therapy (6 weeks to 12 months) - no controlled trials  Superficial skin infections sometimes treated with monotherapy but generally combination therapy with 2 or more of the following antibiotics indicated: macrolides, tetracyclines, sulfonamides, ethambutol

Erythematous, tender lesion on L hand Take Home Points from mid to distal fifth digit with overlying  M. marinum often goes undiagnosed for many years necrotic scab and minimal serous drainage  Negative AFB culture cannot be used to rule it out References  Early diagnosis and treatment is crucial, as it can 1. Sette CS, Wachholz PA, Masuda PY, da Costa Figueira RBF, de Oliveira Mattar FR, Ura DG. Mycobacterium marinum infection: a case report. The Journal of Venomous Caseating granuloma on pathology Animals and Toxins Including Tropical Diseases. 2015;21:7. doi:10.1186/s40409-015-0008-9. 2. Aubry A, Chosidow O, Caumes E, Robert J, Cambau E. Sixty-three Cases of Mycobacterium marinum InfectionClinical Features, Treatment, and Antibiotic Susceptibility cause severe deeper infections in rare cases of Causative Isolates. Arch Intern Med. 2002;162(15):1746–1752. doi:10.1001/archinte.162.15.1746.