770 
DISEASES OF THE FOOT. 
opening, prevent escape of pus, and facilitate the production of purulent 
cellulitis. . To remedy this, nothing succeeds better than steady pressure, 
assisted, if necessary, by astringents like alum and tannin, or even by 
nitrate of silver. Dusting the granulations with iodoform or other dis¬ 
infectant powder also helps to combat the inflammation. Very special 
care is called for when the pus is offensive. Foot-baths are useful on 
account of their cleansing the point attacked, but as they favour prolapse 
of soft tissues, a pressure dressing should he applied. As soon as 
suppuration stops, the soft parts must be protected by means of a 
dressing of tar and tow, until they again become covered with horn. 
This dressing should not be removed until the wound has thoroughly 
cicatrised, when a well-fitting shoe, protecting the diseased point until 
the new horn becomes sufficiently strong, is applied. 
In gangrene of the sensitive sole, the affected point must be com¬ 
pletely exposed, any dead tissue removed, and the freest possible exit 
given to gangrenous discharge. The gangrene may be recognised by the 
greyish yellow colour of the soft structures, and by the pain and bleeding 
which follow any interference with the spot, Necrotic portions of tissue 
are grasped with dressing-forceps and forcibly removed, after which the 
parts are treated as described. 
The treatment of cases complicated with purulent cellulitis of the 
fibro-fatty frog is described in the chapter on “picked-up” nails ; that of 
the subcoronary connective tissue under that title. 
I.—PRICKS OR STABS IN SHOEING. 
The sensitive portions of the foot are often injured during shoeing by 
misdirected nails, with consequences of a very varying character. The 
chief factor appears to be the degree of injury, though infection plays 
no inconsiderable role in determining the result. When the nail only 
penetrates the neighbourhood of the rete mucosum, or injures this alone, 
a superficial inflammation results, with the above-described consequences. 
But if, instead, portions of the cuticular structures containing connective 
tissue are affected, the usual, though not invariable, result is an attack 
of parenchymatous inflammation. The attack may often be avoided by 
immediately withdrawing the nail and closing its track by tar, wax, or 
by burning the horn, thus preventing infection of the wound ; a proof 
that it is not the injury, but the infection it facilitates, which causes 
inflammation. A second nail should not he driven at the same spot, as 
it would again open the path for infection. 
The os pedis is occasionally injured by driven nails, though necrosis 
resulting from inflammation should not be mistaken for fracture produced 
by a nail. 
