Description

A patient with pyomyositis may present with a number of clinical findings that change as the infection progresses.


 

Clinical stages progressing over days to weeks:

(1) invasion (early)

(2) suppuration (evolving)

(3) systemic manifestations with fully developed abscess

 

Initially there is cramping with mild pain and tenderness in the involved muscle without fever.

 

This is followed by low-grade fever, swelling, and increasing pain with tenderness. The affected muscle becomes indurated and firm ("woody").

 

Finally the area becomes fluctuant with erythema and marked tenderness. The person may show signs of sepsis with fever, malaise and chills.

Local Findings

Pain and Tenderness

Fever

Systemic

Stage

cramping

mild

none

none

invasive

swelling and induration

moderate

low grade

none

suppurative

fluctuant, erythema

marked

present

present

fully developed systemic

 

Sometimes a patient may present acutely with systemic findings without preceding stages.

 

A CT or MRI scan can be helpful in establishing the diagnosis and determining the extent of involvement.

 

Differential diagnosis:

(1) muscle strain

(2) synovitis

(3) thrombophlebitis

(4) neoplasm

 


To read more or access our algorithms and calculators, please log in or register.