Abstract
Pyogenic abscess formation is a known but rare complication following childhood immunization.
We present a retrospective review of seven infants in Singapore with methicillin-sensitive
Staphylococcus aureus abscesses following a 5-in-1 vaccine (diphtheria toxoid-tetanus toxoid-acellular
pertussis, inactivated Poliomyelitis and Haemophilus influenzae type b) administration in the thigh that required surgical drainage. The children
were 4 to 7 months old at the time of diagnosis. All of them presented with thigh
swelling and fever was manifested in six infants. Four patients had ultrasound examination
prior to surgery. A breach of sterility during immunization at one center most likely
accounted for a cluster of four cases. Health care personnel should have a high index
of suspicion for post-vaccination abscess especially in a child that presents with
limb swelling, with or without fever, and with a history of recent vaccination in
the same limb. An ultrasound examination to diagnose intramuscular abscess is recommended
for equivocal cases. Prevention strategies include strict adherence to sterility during
immunization and timely reporting of post-vaccination abscesses to health care authorities.
Keywords
Vaccination - abscess - surgical drainage
