What is the Origin of Sterile Abscess?

The term is a compound of 'sterile' (meaning free from living microorganisms) and 'abscess' (derived from the Latin abscessus, meaning a going away or collection of pus). It originates in clinical pathology and infectious disease, where it is used to differentiate an aseptic, chemically-induced inflammatory nodule from a true septic infection. The phenomenon became particularly relevant in endocrinology with the widespread use of high-concentration, non-aqueous hormone preparations.

What is the Mechanism of Sterile Abscess?

The mechanism involves a non-infectious, localized inflammatory response where the body attempts to wall off the foreign or irritating substance. The high concentration or poor solubility of the injected material, such as a crystalline steroid suspension, can cause local tissue irritation and cellular necrosis. This tissue damage triggers the recruitment of inflammatory cells, including neutrophils and macrophages, which form the characteristic pus-filled cavity without the presence of replicating pathogens, leading to a palpable, painful nodule that requires clinical differentiation from an infection.

Sterile Abscess ∞ Area

Sterile Abscess

Meaning

A Sterile Abscess is a localized collection of pus that forms within tissues, typically at an injection site, but which yields no microbial growth upon standard microbiological culture, meaning it is not caused by a bacterial or fungal infection. This inflammatory reaction is a common complication in hormonal health when administering intramuscular or subcutaneous injections of various therapeutic agents, particularly oil-based steroid formulations. The underlying cause is usually a localized foreign body reaction to the injected substance, the oil vehicle, or irritating excipients, rather than a true infectious process.