H.L.FOO1, H.L.KWONG2, J.Y.PAN1
National Skin Centre1, Changi General Hospital2
We aim to characterise patients with cutaneous non-tuberculous mycobacterial infections treated in our centre, looking at clinical characteristics, treatment responses and also possible risk factors.
A retrospective epidemiological study conducted from 2015-2020 to characterise the patients seen in the National Skin Centre for cutaneous NTM infections.
61 patients were diagnosed and treated for cutaneous NTM infections during this period. The top two common clinical presentations were verrucous and granulomatous plaques. 18% (n=11) of our patients reported preceding trauma as risk factor for acquiring the infection. 54% (n=33) patients had culture positive NTM infections, while 46% (n=28) were deemed to have clinical suspicion for but culture negative NTM infection that responded to NTM antibiotic regimens. For patients with culture proven NTM infections, 30.3% grew mycobacterium marinum, 24.2% mycobacterium hemophilus, 21.2% had a mixture of mycobacterium chelonae, abscesses, marinum and ulcerans, 15.2% grew mycobacterium abscesses, 6% mycobacterium chelonae and 3% mycobacterium fortuitum. 63.9% (n=39) of our patients showed treatment response within 3 months of antibiotic therapy and the longest time for treatment response was 8 months for 1 patient.
To date, culture remains to be the gold standard of diagnosis for cutaneous NTM infections. However, close to half of our patients with clinical response to antibiotic regimens did not have culture positive results. Hence, clinical suspicion taking into account risk factors (e.g. preceding trauma), typical clinical and histological features are crucial in the diagnosis of cutaneous NTM infections.