Age: 73.0
Sex: M
Vaccine: FLUX, FLUX, FLUX, FLUX, FLUX
Symptoms: Injection site nodule, Injection site pain, Joint range of motion decreased, Muscular weakness, Reflex test normal
Clinical narrative: Case number PHHY2014US079962 is an initial literature report received on 20 Jun 2014. In this article the author discussed injection induced axillary nerve injury after a drive-through flu shot. This report refers to a 73 year old right-handed man. He had not seen a physician for the past 15 years and he never had any regular screenings performed, but he received annual flu shots. He also reported no preceding infectious disease, recent travels or contact with sick people. There was no specific trauma or other history of recent injections to his shoulder. On an unknown date, he received a flu shot (manufacturer and batch number: not reported, hence conservatively taken as influenza virus vaccine seasonal INN) in his left shoulder (deltoid). On an unknown date, directly after the injection, he experienced severe local pain at the injection site/ left shoulder pain, abduction weakness and felt like he had a knot in his shoulder. He never developed a rash at the injection site, but about 05 weeks after the vaccination, he was not able to abduct his left arm. His other extremities were unaffected and he had no neck or radicular pain or other symptoms. On physical examination, the patient pointed to the area of pain at the midpoint of his left deltoid insertion, which was slightly tender to palpation. There was notable atrophy of the left deltoid muscle, sensory loss on the lower half of the deltoid muscle. The patient had active range of motion of the first 10 degrees of shoulder abduction but could not abduct beyond that. He scored a 2 on the manual muscle test (MMT) of the deltoid, indicating poor function (25%). Passive flexion of the shoulder was normal. Flexion and extension of the forearm and rotatory movement of the shoulder were normal. Deep tendon reflexes for his bilateral biceps brachii, brachioradialis and triceps were all normal and symmetrical (2+ grade). Other than elevated blood pressure; there were no other abnormal findings. The patient declined to undergo further diagnostic testing, including nerve conduction studies and magnetic resonance imaging. He was treated symptomatically with analgesics and occupational therapy, including passive and active range of motion exercises. On the basis of the patient's medical history, physical examination, reported immediate pain at the time of injection, secondary isolated arm abduction weakness and deltoid atrophy suggested that the patient experienced axillary nerve injury by direct needle trauma. It was hypothesize that the likely site of injury in the patient was the anterior branch of the axillary nerve. However, injectate-related chemical neuropathy and shoulder injury related to vaccination administration (SIRVA) were also considered as possible diagnoses. At 01 month follow up, his deltoid muscle showed slight improvement in contraction, sensation, atrophy, and pain. at 06 weeks after initiation of occupational therapy, the therapist reported greatly improved flexion. He was able to achieve 120 degrees of active left shoulder flexion in a seated position with a MMT score of 04, indicating good function (75%). In conclusion the author stated that most adult vaccinations were administered intramuscularly in the deltoid and were generally safe, rare complications, such as nerve injury, may occur more frequently in the future as vaccinations were promoted. Practitioners should be aware of reporting systems, such as VAERS, so that ongoing standardization and quality control of vaccinations can occur. Nerve injury by intramuscular injection was a serious and preventable complication that occurs worldwide and was likely to become more frequent with increased use of intramuscular vaccinations. To address this potential problem, personnel who administer vaccinations should receive competency-based training and education. Alternative routes of administration may be considered to lessen risk.