Wood You Believe It? A Case of a Sporotrichosis Mimic

<i>Mycobacterium marinum</i> is an acid-fast bacillus. Human infection can occur when damaged skin is exposed to an aqueous environment that is contaminated by the organism. An infection with <i>M marinum</i> can present as painless purple nodules that spread along the lymphatics. Sporotrichosis presents similarly. We present a case of cutaneous <i>M marinum</i> infection in a patient from rural central Texas who developed lesions initially suspected to be sporotrichosis after she sustained a splinter wound of her right hand. Despite empirical treatment for sporotrichosis with itraconazole, the patient's condition worsened, prompting further investigation. A positive culture for <i>M marinum</i> altered the treatment plan. After a course of minocycline, the patient's cutaneous lesions resolved. This case highlights the diagnostic challenge of <i>M marinum</i> infections, which can mimic conditions such as sporotrichosis. <i>M marinum</i> is an incredibly slow-growing organism in culture and requires a high degree of foresight for accurate diagnosis. Clinicians should consider <i>M marinum</i> in the differential diagnosis for patients with apparent sporotrichosis lesions, particularly those with a history of appropriate environmental exposure, even in regions distant from bodies of water or occupations not routinely in contact with aquatic organisms.