I found Kathy Dettwyler's remarks about breast usage in scheduled vs
frequent-feeding cultures extremely relevant to the issue of development of
mastitis.  When one considers the etiology of inflammatory disorders of
other  organs of the body, and the potential progression to true infection
which then becomes a risk, the breast no longer looks so exotic.

 Consider the bladder.  If a person habitually delays urination, patterns of
inflammation can occur which then make thorough voiding difficult.  Retained
urine then becomes a potential gowth medium for bacteria.  If the immune
system is taxed or the bladder is mechanically bruised (bike riding, sex,
tight pants,) the person may become febrile, have headache, experience pain,
and the flow of urine may become so blocked that they need interventions of
various kinds.  This scenario is repeated in the nasal sinuses.  The nasal
sinuses drain (on a normal day) about a quart of mucus down the back of the
throat quite unnoticed.  If the sinus passages swell due to a cold or
allergies, the mucus can't drain.  The first sx are headache, local
tenderness, heat.  If the mucus sits too long, the potential increases for
bacteria to multiply and the inflammation progresses to infection -- esp. if
the immune sx is stressed.  The antibiotic therapies for both these
disorders hits the condition from two angles: reduction of inflammatory sx
and bacteriocide.  The concept holds true that for any organ of the body
fluid stasis is going to be a big problem.

The new mother is in an depressed state immunilogically -- both due to
stress of labor and delivery and due to the fact that there is some
compromise of the immune sx during preg. to protect rejection of the fetus,
and this takes a while to recover from.  The  wearing of bras (esp to bed)
creates bruising and obstructs ducts.  The insanity of our (lack of)
postpartum care has mothers over-doing way too soon.  Add to this the
typical poor instruction women have on latch-on technique AND scheduled
feeds, and it is no wonder that Jan Riordan found that women report much
higher incidences of mastitis (up to 33%) than the literature describes
(about 3%.)  It goes unreported, or is self treated, or managed over the phone.

If you add a cracked nipple to the mix, you do have a portal of entry for
bacteria.  If I cut my finger, blood flows out.  Some have asked how
bacteria can float against the milk stream up into the interior of the
breast to contribute to infection.  My finger can certainly get infected
through a break in the skin, and infection can enter against the directional
stream of the blood, and I can get infection there that will spread up my
whole arm if not treated.  Sometimes I think we don't do enough logical
thinking about matters involving the breast.  It is still skin, and tissue,
and it mostly acts like other skin and tissue elsewhere in the body.

Barbara

Barbara Wilson-Clay, BS, IBCLC
Private Practice, Austin, Texas
Owner, Lactnews On-Line Conference Page
http://moontower.com/bwc/lactnews.html