Musculoskeletal ultrasound prompts a rare diagnosis ofMycobacterium marinuminfection

Abstract

Mycobacterium marinum is an atypical mycobacterium predominant in aquatic environments that can be acquired by contact with contaminated water, causing skin infections or, less commonly, deeper infection of tendons and joints. Although M. marinum has been recognized as a mimicker of inflammatory arthropathy (1-4), the diagnosis of infection requires a high index of suspicion and is often delayed, resulting in unsuccessful regimens of immunosuppression and a prolonged clinical course. We present a case of M. marinum-induced tenosynovitis with cutaneous manifestations, which at first was highly suggestive of rheumatoid arthritis (RA) until the use of musculoskeletal ultrasound (MSK-US) by a rheumatologist brought that diagnosis into question and appropriately delayed immunosuppressive therapy. Subsequent work-up including biopsy and culture of a skin lesion differentiated the correct infectious diagnosis from inflammatory arthropathy, and ensured appropriate antibiotic treatment in a timely fashion.A 53-year-old man was referred to our rheumatology office for evaluation of a subacute asymmetric polyarthropathy, predominantly affecting the right metacarpophalangeal (MCP) joints. Two months prior to presentation, the patient palpated a nodular subcutaneous mass proximal to his right dorsal second MCP, with subsequent development of swelling and pain of that MCP. Naproxen and a brace provided partial relief, but the swelling and pain spread to other MCP joints, to some proximal interphalangeal (PIP) joints, and the wrists, predominantly of the right side. He had difficulty making a fist, and the stiffness was significantly worse each morning for hours. Review of systems was negative for fever, weight loss, skin rash, alopecia, oral ulcers, dry eyes, dry mouth, photosensitivity, Raynaud's phenomenon, or constitutional symptoms.The patient's past medical history was unremarkable. His only medication was naproxen. He had no drug allergies. The patient had no history of tobacco smoking, alcohol or drug abuse, or any family history of autoimmune disease or inflammatory arthritis.On examination, the patient had substantial swelling and tenderness of the right second, third, and fifth MCP joints, with limited flexion of all digits, but no swelling or

Rare diagnosis of nodular lymphangitis caused by Mycobacterium marinum: MDCT imaging findings

“…A characteristic clinical presentation and a proper exposure history may suggest the diagnosis of M. marinum infection. Furthermore, ultrasound findings such as tenosynovitis with the presence of “rice bodies” have recently been reported in a patient (10); this finding can be characteristic though not specific, being so in other mycobacterial infections or rheumatoid arthritis. However, there are no pathognomonic clinical or imaging features and definitive diagnosis depends on histopathological and microbiological tests from skin biopsies.…”

Evaluation of early manifestations of spreading pattern Mycobacterium marinum infection by ultrasonography

“…Mycobacterium marinum is a pathogenic mycobacterium found in skin and soft tissue infections and is associated with fish and bodies of water. 1 Mycobacterium marinum infections can be divided into four types: a solitary papulonodular lesion, sporotrichoid form, deep infection, and disseminated infection. In about 25% of patients, the infection manifests in the sporotrichoid form.…”