Isolated abscess in superior rectus muscle in a child

Pyomyositis is a primary bacterial infection of striated muscles nearly always caused by Staphylococcus aureus. Development of the intramuscular abscess involving the extra-ocular muscles (EOMs) remains an extremely rare process. We herein present a case of isolated EOM pyomyositis involving superior rectus muscle in a 2-year male child who was referred with complaints of swelling in left eye (LE) and inability to open LE since last 1-month. Orbital computed tomography (CT) scan showed a well-defined, hypo-dense, peripheral rim-enhancing lesion in relation to left superior rectus muscle suggestive of left superior rectus abscess. The abscess was drained through skin approach. We concluded that pyomyositis of EOM should be considered in any patient presenting with acute onset of orbital inflammation and characteristic CT or magnetic resonance imaging features. Management consists of incision and drainage coupled with antibiotic therapy.