Q: My 23 years old daughter suffered from tuberculosis in 2006 – she got a cold abscess. A year after the abscess surgery, she has again developed a cold abscess between her shoulder and neck. She was operated upon again and once again was diagnosed with TB. Although the treatment has been started, AFB test result is awaited. Why has TB recurred?

A:Cold abscesses occur due to infection by Mycobacterium tuberculosis. They are called "cold" because in comparison to the other common abscesses due to pyogenic bacteria such as Staphylococcus or Streptococcus they generally do not exhibit the cardinal signs of inflammation such as raised temperature at the infection site, pain, redness. Reappearance of the disease at the same site might be due to surgical causes or microbiological causes. Among the microbiological causes it could be due to a) disease recurrence, b) reinfection with same or related organism, c) infection by a different organism. One of the important microbiological causes of recurrence of the cold abscess could be drug resistant TB. It would be important to know the drug sensitivity of this organism. This could be done either by culture or by PCR based methods.

Among surgical causes: recurrence of cold abscess after surgery may occur following aspiration of the abscess, or resection. In some cases it has been seen that the recurrence rates are higher in case of aspiration of the abscess, and in cases of incomplete resection or surgery. However, each case is different and unique so the surgeon is in the best position to decide if complete resection is possible or indicated.

Appropriate management of cold abscess cases would include good microbiological diagnostic facility (based on microscopy, culture, drug sensitivity testing, or PCR), medical treatment (this involves taking the right anti-tuberculous medications at the correct dose and duration) and surgical management.

Finally reappearance of a disease at the same location does not necessarily mean recurrence. Other infective or non-infective conditions need to be excluded.