Delayed Diagnosis of Scrofuloderma Misdiagnosed as a Bacterial Abscess

An 82-year-old woman presented with a four-month history of an ulcerative plaque overlying her left neck. This lesion had developed as a subcutaneous nodule, gradually increased in size, and evolved into ulcers. Before visiting our Dermatology clinic, the patient had been diagnosed as having a bacterial abscess, but treatments with antibiotics were unsuccessful. The presence of a purulent discharge and prominent ulceration caused further confusion as bacterial abscess, and radiologic evaluation on computed tomography also led to the possibilities of secondary lesions from an abscess or malignancy. However, the characteristic appearance of her lesion allowed us to discern cutaneous tuberculosis, especially scrofuloderma. Based on clinical examinations, staining for acid-fast bacilli, and positive findings of polymerase chain reaction, a quick diagnosis of scrofuloderma was made. After that, she was treated successfully with anti-tuberculosis therapy and the ulcer healed. Our case highlights the problem of delayed diagnosis of scrofuloderma presenting as a bacterial abscess. In conclusion, having a high index of suspicion is needed to diagnose cutaneous tuberculosis correctly.

Magnetic resonance spectroscopy in the diagnosis and etiological definition of brain bacterial abscesses

We report two patients with bacterial brain abscesses whose etiological diagnosis was correctly proposed by association of diffusion weighted images (DWI) and magnetic resonance spectroscopy (MRS) with conventional MRI. Both patients presented ring enhancing lesions with evidences of restricted diffusion. On MRS, the abscess caused by aerobic bacteria presented lactate and aminoacids peaks and the abscess caused by anaerobic facultative bacteria showed also acetate and succinate peaks. These results are in agreement with an unique previous study that related MRS pattern with bacterial etiology. Conventional MRI, associated with DWI and MRS is effective in diagnosing bacterial abscess and promising in exploring its etiology.

Apresentamos dois pacientes com abscessos bacterianos cerebrais cujos diagnósticos etiológicos foram corretamente auxiliados pela associação de difusão e espectroscopia à ressonância magnética convencional. Ambos apresentavam lesões com captação anelar de contraste e evidências de restrição à difusão de moléculas de água. Na espectroscopia, o abscesso causado por bactéria aeróbia apresentou picos de lactato e aminoácidos, enquanto o abscesso causado por bactéria anaeróbia facultativa mostrou, além destes, picos de acetato e succinato. Tais resultados concordam com um único estudo prévio que relacionou o padrão de espectroscopia nos abscessos com sua etiologia bacteriana. A ressonância magnética convencional, associada à difusão e à espectroscopia é uma técnica eficiente no diagnóstico de abscessos bacterianos e promissora em explorar suas etiologias.