Facial scrofuloderma

Cutaneous tuberculosis (CTB) is an uncommon condition with a wide clinical spectrum, constituting 1%–2% of all extrapulmonary manifestations.1 The diagnosis of CTB has become an enormous challenge since it can mimic various dermatoses such as discoid lupus erythematosus, psoriasis, bacterial abscesses, malignancy, and other skin infections.2 Here, we report a case of facial scrofuloderma, an uncommon presentation. A 23-year-old man was admitted to our hospital complaining of a painful ulcer with progressive growth on his face and two lumps that appeared on the left mandibular and submental areas and developed into abscesses over 4 weeks. The patient had received various courses of antibiotics without any improvement. He had no previous history of immunosuppressive therapy and tuberculosis, but his grandfather had a history of pulmonary tuberculosis and had died 5 years ago. Physical examination revealed an ulcer of 2 × 1.5 cm on the left face and two abscesses of 2 × 3 and 2 × 1.5 cm on the left mandibular and submental areas, respectively (Figure 1A). Laboratory evaluation showed increased white blood cell (11.1 × 109/L), neutrophilic granulocytes (70%), and a mildly elevated high-sensitivity C-reactive protein level. He tested negative for HIV and syphilis and showed positive results in the T-SPOT.TB test. Chest computed tomography (CT) showed normal findings with no signs of lung tuberculosis. The sputum smear was negative for acid-fast bacilli, as was the sputum culture. Skin biopsy revealed multiple granuloma formation with epithelioid cells, multinucleated giant cells, and lymphocytes around them in the dermis, forming an abscess with a histiocytic infiltrate around the lesion (Figure 2A,B). Facial and cervical CT showed enlarged lymph nodes in the left parotid gland, bilateral neck, and the right submandibular and submental areas with fistula formation. Submental lymph node biopsy revealed palisading granulomas with caseous necrosis and a lymphocytic infiltrate (Figure 2C), while tissue acid-fast bacilli staining for the lymph node showed positive results (Figure 2D). The mycobacterial culture of lymph node and skin tissue both grew Mycobacterium tuberculosis complex, and polymerase chain reaction (PCR) showed the same results. On the basis of the clinical, pathological and bacteriological findings, a final diagnosis of scrofuloderma secondary to lymph node tuberculosis was made. The patient was treated with antituberculous drugs, namely isoniazid, rifampicin, pyrazinamide, ethambutol, and moxifloxacin, for 9 months and showed good improvement (Figure 1B). CTB may manifest as an endogenous or exogenous condition. Endogenous CTB occurs secondary to an already existing infection of the body, with transmission occurring through contiguous, lymphatic, or hematogenous dissemination. Exogenous CTB occurs through direct inoculation of bacilli into the skin of susceptible individuals.3 The clinical manifestations of CTB are varied and complicated, which make the diagnosis a great challenge. The scrofuloderma seen in our case was a type of cutaneous tuberculosis resulting from direct mycobacterial spread from organs under the skin, such as the lymph nodes,4, 5 and it occurs commonly in the neck, chest, and axilla region. However, the appearance of this condition on the face is unusual. The incidence of extrapulmonary tuberculosis shows a much stronger relationship with HIV infection, emergence of multidrug-resistant tuberculosis, and immunosuppressive treatment.3 However, the patient in our case had normal immune function. CTB presents a wide range of clinical manifestations, mimicking other chronic dermatoses and leading to delayed diagnosis. The differential diagnosis in this case should include abacterial abscess and lymphoma. As stated above, the patient showed no effect of treatment with various antibiotics, while the results of tissue culture ruled out the possibility of abacterial abscess and the pathological findings led us to rule out the diagnosis of lymphoma. This further signified the importance of high clinical suspicion for cutaneous tuberculosis. The recommended treatment for cutaneous tuberculosis is currently limited to conventional oral antituberculosis therapy and occasional surgical intervention in cases that require it.6 Our patient was successfully treated with antituberculosis therapy and is still undergoing follow-up. This work was sponsored by grants from National Natural Science Foundation of China (No. 81803120, 82173405), Shanghai Tenth People's Hospital Pan Deng Ren Cai Foundation 2021SYPDRC025. The authors have no conflict of interest to declare. Authors declare human ethics approval was not needed for this study. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.