Adverse reactions after diphtheria, pertussis, tetanus, polio vaccination at 18 months of age were investigated in three groups: 74 children injected in the deltoid muscle with a 16-mm (5/8-in) needle, 64 in the anterolateral thigh with a 16-mm needle, and 67 in the anterolateral thigh with a 25-mm (1-in) needle. No significant differences in systemic reactions were observed. Severe pain occurred in 30.5% of the groups injected in the thigh compared with only 8.1% of the group injected in the arm (P < .001). Children vaccinated in the thigh had decreased movement of the extremity significantly more often than those injected in the arm (49.9% v 25.6%, P < .005), and two thirds of the former limped for 24 to 48 hours. Redness and swelling were observed more often after injection in the arm than in the thigh (58.1% v 26.7%, P < .0005). The only effect of changing needle length in the groups injected in the thigh was the occurrence of more redness and swelling in children vaccinated with the 16-mm needle compared with the 25-mm needle. Overall, parents rated more reactions as moderate to severe among children injected in the thigh than among children injected in the arm (64.2% v 37.9%, P < .001). The deltoid muscle appears to be the preferred site for administration of diphtheria, pertussis, tetanus, polio vaccine at 18 months of age.
- Received December 23, 1987.
- Accepted March 2, 1988.
- Copyright © 1989 by the American Academy of Pediatrics