Post-vaccination Tubercular Cold Abscess of Thigh of An Infant

We report a case of post immunization tubercular soft tissue cold abscess on a lateral part of the right thigh in an eight-month-old male baby following third dose of intramuscular Hepatitis B vaccination. The baby presented with gradual onset of fever for 10 days after hepatitis B vaccination this was followed by an erythematous, painless, firm small swelling on the anterolateral part of the right thigh which grew gradually to a size of 2 × 2.5 cm size. The baby was treated with empirical antibiotics (Amoxicillin) following which fever subsided but there was no improvement in swelling so the baby was advised for various laboratory investigations. The aspirate from the abscess was subjected to Acid fast staining using microscopy (Ziehl-Neelsen staining) that revealed Acid Fast Bacilli (2+). In addition (Cartridge Based Nucleic Acid Amplification Test) confirmed the presence of M. tuberculosis complex sensitive to Rifampicin. J Microbiol Infect Dis 2020; 10(4): 234-236.