Tuberculous dactylitis

Tuberculous dactylitis is a form of tuberculosis that affects the bones in the fingers and toes. It is also known as spina ventosa, a term derived from Latin, meaning "wind-filled spine," due to the cystic expansion of the bone observed in this condition. This disease is a rare manifestation of extrapulmonary tuberculosis, which means it occurs outside of the lungs. Tuberculous dactylitis is more commonly seen in children and young adults, reflecting the demographic most susceptible to skeletal forms of tuberculosis.

Etiology and Pathogenesis

Tuberculous dactylitis is caused by the bacterium Mycobacterium tuberculosis. The bacteria reach the bones of the fingers or toes through the bloodstream from a primary site of infection, often the lungs. This dissemination can occur due to a weakened immune system, which might be compromised due to malnutrition, HIV infection, or other factors that impair the body's defenses.

Clinical Features

Patients with tuberculous dactylitis typically present with swelling of the affected digits, accompanied by pain and reduced range of motion. The disease progresses slowly, and the swelling is usually not accompanied by redness or warmth, distinguishing it from acute bacterial infections. In advanced cases, abscess formation and sinus tract development may occur, leading to discharge of pus from the affected area.

Diagnosis

Diagnosis of tuberculous dactylitis involves a combination of clinical examination, imaging studies, and microbiological tests. X-rays of the affected digits may show expansion of the bone and areas of bone destruction, characteristic of the disease. Magnetic resonance imaging (MRI) can provide more detailed images and help assess the extent of the infection. Confirmation of the diagnosis is achieved through the identification of Mycobacterium tuberculosis in tissue samples obtained from the affected area, either by culture or molecular methods.

Treatment

The treatment of tuberculous dactylitis involves a prolonged course of antituberculous therapy, typically lasting 6 to 9 months. The standard regimen includes a combination of antibiotics such as isoniazid, rifampicin, pyrazinamide, and ethambutol. Surgical intervention may be necessary in cases with extensive bone destruction or abscess formation, to debride necrotic tissue and drain abscesses.

Prognosis

With timely and appropriate treatment, the prognosis for tuberculous dactylitis is generally good. Most patients achieve complete resolution of symptoms and restoration of function in the affected digits. However, delays in diagnosis and treatment can lead to permanent deformity and functional impairment.

Prevention

Prevention of tuberculous dactylitis involves controlling the spread of tuberculosis through public health measures such as vaccination, prompt diagnosis and treatment of active tuberculosis cases, and screening and treatment of latent tuberculosis infection in high-risk populations.