Delayed focal lipoatrophy after AS03-adjuvanted influenza A (H1N1) 2009 vaccine.

Intramuscular vaccination may lead to loss of subcutaneous fat resulting in skin depression at the site of injection. We report for the first time a delayed lipoatrophy after with AS03-adjuvanted influenza A (H1N1) 2009 vaccine. Inadequate administration into the adipose tissue may be causative. During next pandemic, education to optimal intramuscular administration and prolonged monitoring of adverse effects could be proposed.