Prognostic factors of mycobacterium marinum infection of the hand and wrist

Abstract

Introduction: There is inadequate information on prognostic factors of Mycobacterium marinum infection in the literature. The objective of this study is to identify prognostic factors that affect the functional outcome of this condition. Methods: 166 patients treated from 1981 to September of 2009 were included in this prospective study. Inclusion criteria include exposure to marine environment, history of trauma and positive histology of granulomata by biopsy or culture for mycobacterium marinum. Exclusion criteria include positive culture of organisms other than mycobacterium marinum. Statistical analysis was performed by SPSS version 16.0. Mann-Whitney U nonparametric test and X2 test were used. A P-value of <0.05 was significant. Results: Positive marine exposure was associated with earlier presentation (median of 2 months versus 3.5 months, p=0.001) and less resulting deformity (no deformity versus residual stiffness, p=0.03). Incorrect diagnosis was seen in 100 (60.2%) patients and usually presented late (41 of 98 patients presented later than 3 months). The use of steroid injections was associated with incorrect diagnoses (P=0.000). Patients given steroid injections prior to admission resulted in more debridements (2 versus 1; P=0.026), more deformity (stiffness versus no deformity; P=0.000) and longer antibiotic duration (7 months versus 6 months; P=0.017). Conclusion: Positive marine exposure was associated with earlier consultations and this lead to less deformity. Misdiagnoses such as trigger finger would lead to intralesional steroid injections, ultimately prolonging antibiotic duration, leading to more debridements and further residual deformities.