Tuberculous gumma

Tuberculous Gumma

A tuberculous gumma is a rare manifestation of tuberculosis (TB), characterized by a localized, tumor-like lesion in the skin or subcutaneous tissue. It is a form of cutaneous tuberculosis, which occurs when the Mycobacterium tuberculosis bacteria infect the skin.

Pathophysiology

Tuberculous gummas are formed when the immune response to the tuberculosis bacteria is insufficient to completely eradicate the infection, leading to the formation of a granulomatous lesion. These lesions are typically firm, painless, and can vary in size. They are often found in individuals with a compromised immune system or in those with a high bacterial load.

Clinical Presentation

Patients with tuberculous gumma may present with one or more nodules that can ulcerate and discharge pus. The lesions are usually found on the extremities, trunk, or face. Diagnosis is often confirmed through a biopsy of the lesion, which reveals caseating granulomas, and by identifying the presence of Mycobacterium tuberculosis through polymerase chain reaction (PCR) or culture.

Diagnosis

The diagnosis of tuberculous gumma involves a combination of clinical examination, histopathological analysis, and microbiological tests. A skin biopsy is essential to observe the characteristic histological features, such as caseating necrosis and granuloma formation. Ziehl-Neelsen stain may be used to detect acid-fast bacilli, although they are not always present in the lesions.

Treatment

The treatment of tuberculous gumma is similar to that of other forms of tuberculosis and involves a combination of antitubercular therapy (ATT). The standard regimen includes drugs such as isoniazid, rifampicin, ethambutol, and pyrazinamide. The duration of treatment is typically six to nine months, depending on the severity and response to therapy.

Prognosis

With appropriate treatment, the prognosis for patients with tuberculous gumma is generally good. However, delayed diagnosis or inadequate treatment can lead to complications, including the spread of the infection to other parts of the body.

Related Pages

• Tuberculosis
• Cutaneous tuberculosis
• Granuloma

References

A tuberculous gumma on the skin.