Tropical pyomyositis. Demonstration of extent and distribution of disease by gallium scintigraphy.

Pyomyositis is a Staphylococcus aureus infection of muscles reported primarily in tropical countries but seen with increasing frequency in temperate climates. Because of its rarity in the United States, the diagnosis may not be considered immediately, and involved muscles may break down and become abscessed. Diagnosis is most reliably made by the recovery of pus from a muscle aspirate. Ga-67 scan findings of an interesting case of pyomyositis involving many muscle groups in both upper and lower extremities is reported. Despite arthralgias and complicating adult respiratory distress syndrome, Ga-67 correctly localized the infection to muscles in the shoulders, upper thorax, buttocks, and thighs. A bone scan was negative, excluding the possibility of extension of the infection to bone.