A 46-year-old fisherman came to dermatovenereology outpatient clinic with a chief complaint of a raised red-purple rough spot on the right knee as well as reddish patches on the left foot for almost 20 years before admission. The lesion initially appeared on the right knee as small and soft lumps which subsequently elevated and grew larger in size. Moreover, the lesion easily bled upon minor trauma and eventually produced pus mixed with blood. The patient sometimes complained of itching but no pain was reported. The patient denied a history of long-standing cough, bloody cough, night sweats, weight loss, and there was no history of TB treatment. Patient also denied any histories of allergy to food or drugs as well as history of family with the same complain. History of immunization was unknown. The patient had been treated at the local hospital in multiple occasions with both oral medication and ointments, but the complaints did not show any improvement. The patient was in an otherwise healthy condition with a body weight of 64 kg. Dermatological examination of the right knee showed erythematous plaque with verrucous surface, elevated edge and erythematous base accompanied by crusting. Left dorsum pedis showed erythematous macules and plaques accompanied by crusting (Figure 1). The differential diagnosis of this patient included tuberculosis verrucosa cutis, lupus vulgaris, chromoblastomycosis, and neurodermatitis, with tuberculosis verrucosa cutis as the working diagnosis.
Laboratory test showed leukocytosis (11,350/uL) while other results of complete blood test, blood sugar, and liver functions were within normal range. Examination of pus and skin scraping by Ziehl Nielsen staining did not reveal any acid-resistant bacilli (AFB). Skin scraping examination with 10% KOH revealed no hyphae, spores nor muriform bodies. There was no visible fungus growth in tissue culture with saboraud agar. Chest radiograph did not show any abnormalities (Figure 2A). Mantoux test showed negative result (induration of 9 mm) (Figure 2B). Histopathological examination of skin tissue from the left knee showed pseudoepitheliomatous hyperplasia of the epidermis and diffuse lymphocytic and neutrophil inflammation infiltrate in the superficial dermis extending to the epidermis, perivascular areas, and the interstitial middle and deep dermis. Periodic acid Schiff (PAS) staining did not show presence of fungal elements. The final conclusion of the histopathological examination was suppurative chronic inflammation which can be found in deep mycosis and cutaneous TB (Figure 3A, B). Due to this inconclusive result, further tests in the form of M. tuberculosis culture with skin tissue sample, Interferon-gamma release assays (IGRA) test with ELISA method using blood sample, and examination of M. tuberculosis (MTb) with GeneXpert method using tissue sample, were carried out. MTb examination using GeneXpert method and culture after four weeks failed to demonstrate the presence and growth of M. tuberculosis, respectively. However, the result of IGRA examination was positive.
Based on the history taking, physical examination, and supporting tests, the patient was diagnosed with tuberculosis verrucosa cutis and given category 1 antituberculosis therapy trial. Based on the 64 kg body weight of the patient, four tablets of fixed dose combination antituberculosis drugs each consisted 150 mg rifampicin, 75mg isoniazid, 275 mg etambuthol, and 400 mg pyrazinamide were given once daily for 4 weeks. In addition, B Complex tablet was also prescribed once daily. After 21 days of treatment, thinning of the plaque and significant improvement of the pruritus were observed. In addition, there were no adverse reactions reported by the patient. Therefore, the regimen was continued for two months before being converted to the maintenance phase in the third month. In the maintenance phase, two tablets of fixed combination drugs each consisted of 75 mg isoniazid dan 150 mg rifampicin were given. At the end of the six-month treatment, a significant improvement was evident (Figure 4).