Sternocleidomastoid pyomyositis

Pyogenic myositis (pyomyositis) represents a bacterial infection of striated muscle. Predominantly associated with tropical regions and commonly caused by Staphylococcus aureus, the incidence of cervical pyomyositis is rare. To our knowledge, we report the first case of group A streptococcal cervical pyomyositis in an immunocompetent British Caucasian patient.

A previously well 48-year-old Caucasian male presented with sore throat, left sided neck pain and swelling. He was a lifelong non-smoker with no recent travel or animal exposure. On admission, he was febrile with unilateral neck swelling. Random blood glucose was normal and an HIV test negative. CT imaging confirmed a large heterogeneous mass extending throughout the entirety of the left sternocleidomastoid muscle. The patient underwent exploration and drainage of a large intra-sternocleidomastoid neck abscess. Microbiology identified group A - streptococcus. Histology confirmed abscess formation in muscle with no acid-fast bacilli. The patient recovered well postoperatively and continues to do well.

Cervical pyomyositis is a rare condition that if not treated appropriately may cause internal jugular vein thrombosis, sepsis and death. Pyomyositis requires a high index of suspicion and should be considered a differential diagnosis in any painful swelling in the head and neck region.