Anasarca

Anasarca refers to a state of generalized edema. 

Terminology

Some definitions of anasarca focus on the presence of subcutaneous (body wall and/or extremity) edema ^1,2,7, while others focus on pleural effusions and ascites ³. An overarching definition is the accumulation of fluid (water retention) in various or all tissues and body cavities, without specification of a particular body site ^4-6.

Pathology

Anasarca usually results from capillary filtration/leakage exceeding the amount of fluid removed via lymphatic drainage. Fluid accumulates in the interstitial spaces ("third spacing").

Etiology

The causes of anasarca are various ^2,6:

• nephrotic syndrome
• end-stage renal disease
• heart failure
• cirrhosis
• malnutrition
• hypothyroidism (myxedema)
• inferior or superior vena cava obstruction
• lymphedema due to lymphatic obstruction by tumor or filariasis
• sepsis with fluid resuscitation
• hydrops fetalis

Radiographic features

CT

Anasarca of the body wall manifests as the following, in order of increasing severity ²:

• subcutaneous fat stranding
• pockets of fluid accumulation on the dependent subcutaneous tissues
• fluid accumulation in the intermuscular planes or non-dependent subcutaneous tissues
• circumferential or diffuse fluid collection in the subcutaneous tissues and intermuscular/tissue planes of multiple segments of the torso

In addition, pleural effusions and ascites may be considered, depending on the definition, components of anasarca or as correlated third space fluid sites ².

History and etymology

Anasarca is an abbreviation of the Greek phrase ὕδρωψ ἀνὰ σάρκα (húdrōps anà sárka) ⁸, meaning dropsy throughout the flesh/body. The Greek root sarx (genitive sarkos) is also the origin of sarcoid and sarcopenia.

See also 

• fetal anasarca