Clinical characteristic of cutaneous tuberculosis in a tertiary hospital in East Malaysia between January 2014 and September 2021

Tuberculosis (TB) is an infection predominantly caused by Mycobacterium tuberculosis which commonly causes pulmonary infections. Cutaneous tuberculosis (CTB) is less common and accounts for 1–2% of the total extra-pulmonary cases.1 There are no local data on the clinical characteristics of CTB in Malaysia. We conducted a single-center, retrospective study in a tertiary hospital in East Malaysia to determine the epidemiologic and clinical characteristics of CTB among our local population. All patients diagnosed with CTB between January 2014 and September 2021 were included. Demographic data and clinical characteristics of CTB were recorded and analysed using SPSS software. We recruited a total number of 12 patients for our study. The demographic data were summarised in Table 1. The commonest clinical presentation was TB verrucosa cutis (n = 4, 33%), followed by miliary TB (n = 2, 17%), and scrofuloderma (n = 2, 17%) (Figure 1). Most CTB patients presented with skin lesions over the lower limbs (n = 5, 41.7%), followed by the upper limb (n = 2, 17%). In our study, only 2 (17%) patients had positive TB culture, with negative TB culture in the remaining 10 (83%) patients. Tissue smear for Acid Fast Bacilli was positive in 3 (25%) patients, while 10 (83%) patients had histological findings consistent with granuloma ± caseation from the skin biopsies. All our patients received combined anti-TB medications for 6 to 12 months with a resolution of the skin lesions. The clinical manifestations of CTB are mainly depending on the infection source (endogenous/exogenous), previous exposure, and host immunity.2 It is commonly divided into true CTB and tuberculid diseases. In our study, tuberculous verrucosa cutis (33%) was the commonest clinically morphology of CTB, followed by military TB (17%) and scrofuloderma (17%). In similar studies from other countries, lupus vulgaris is the commonest CTB type.1,3 Another study from Brazil showed that Bazin disease is the commonest manifestation.4 The discrepancy in the predominant subtypes of CTB in our study needs to be confirmed by a large-scale, multicenter study in the future. Most of our patients (83%) had negative TB cultures. The diagnosis of CTB is mainly based on clinical features with the histopathological finding of the skin biopsy which show granuloma with or without caseation. Polymerase chain reaction (PCR) amplification has been proven to be invaluable in the identification of Mycobacterium tuberculosis from skin Clinical characteristic of cutaneous tuberculosis in a tertiary hospital in East Malaysia between January 2014 and September 2021