This bacterial infection is caused by Mycobacterium marinum. Marinum is a relative of the organism which causes tuberculosis. This lesion is often referred to as a swimming pool granuloma. Atypical mycobacterial infections may cause life-threatening disease in people with weakened immune systems (immunocompromised individuals).
Review Date 6/5/2018
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.