Severe pyomyositis caused by Panton-Valentine leucocidin-positive methicillin-sensitive Staphylococcus aureus complicating a pilonidal cyst.

BACKGROUND: To our best knowledge, Panton-Valentine leucocidin (PVL)-positive methicillin-sensitive Staphylococcus aureus (MSSA) has not been described yet as cause for severe pyomyositis.

CASE REPORT: We present a 23-year-old apparently healthy male patient without any typical predisposing findings who developed severe pyomyositis secondary to an operated pilonidal cyst. In the follow-up, the patient showed signs of immunocompromisation. The causative agent for purulent infection of multiple muscles was a MSSA strain harbouring PVL toxin.

RESULTS: In the reported case, aggressive antibiotic and surgical treatment with additional application of immunoglobulins has lead to recovery from the disease without relapse.

CONCLUSIONS: PVL-positive S. aureus are associated with skin diseases, multiple abscesses and often complicated by severe sepsis and necrotising pneumonia. Under such circumstances, the mortality rate can reach up to 75%. In addition, the PVL toxin can cause immunocompromisation and might be therefore involved in the aetiology of pyomyositis. Aggressive antibiotic and surgical treatment with additional application of immunoglobulins is recommended for treatment.