AXILLARY ABSCESS. 5 



Certain abscesses, from their anatomical position, are likely 

 to do grievous harm if allowed to progress unopened by the 

 surgeon. Thus pus in the neighbourhood of joints, which 

 themselves are not inflamed, may track into the articular cavity, 

 and bring about irreparable mischief by setting up suppurative 

 arthritis. Again, a focus of suppuration in the ischio-rectal 

 fossa will most easily find its exit through the bowel wall, causing 

 a troublesome persistent rectal sinus. Pus confined by firm 

 resistent fascia may so press upon important structures as to 

 become a menace to life, as in the case of an abscess beneath 

 the deep fascia of the neck, where it may narrow the trachea 

 and cause urgent dyspnoea. So further, pus within the sheath 

 of a muscle may track widely, and may present at a point very 

 remote from its original starting point, and sinuses extremely 

 difficult to eradicate may be the consequence. Puriform fluid 

 formed deep to the periosteum of a long bone tends rapidly to 

 strip the membrane from the outer surface of the shaft, leading 

 to necrosis. 



The track of pus in certain regions is dealt with on other pages, 

 but its particular course in some may be alluded to in this 

 chapter. 



Axillary Abscess. Superficial axillary abscesses are due to 

 septic inflammation of the large sebaceous glands in the skin. 

 Most commonly the deep ones are dependent upon suppurative 

 lymphadenitis ; sometimes they are due to disease of the ribs or 

 of the shoulder-joint. 



When sufficient pus has been allowed to collect in the axillary 

 space, its presence will cause the hollow of the axilla to become 

 obliterated, and the concavity of its floor to be even converted 

 into a convexity. Further, the anterior wall of the space 

 formed by the pectoralis major will bulge. The abscess will 

 increase also in an upward direction behind the clavi-pectoral 

 fascia, sometimes passing deep to the clavicle into the posterior 

 triangle of the neck. The pus will be hemmed in at the back of 

 the space, because of the attachment of the serratus magnus to 

 the vertebral border of the scapula. (See Fig. 1.) 



