Subcutaneous Whitlow.—In this variety the infection manifests itself as a cellulitis of the pulp of the finger ([Fig. 9], c), which sometimes spreads towards the palm of the hand. The finger becomes red, swollen, and tense; there is severe throbbing pain, which is usually worst at night and prevents sleep, and the part is extremely tender on pressure. When the palm is invaded there may be marked œdema of the back of the hand, the dense integument of the palm preventing the swelling from appearing on the front. The pus may be under such tension that fluctuation cannot be detected. The patient is usually able to flex the finger to a certain extent without increasing the pain—a point which indicates that the tendon sheaths have not been invaded. The suppurative process may, however, spread to the tendon sheaths, or even to the bone. Sometimes the excessive tension and virulent toxins induce actual gangrene of the distal part, or even of the whole finger. There is considerable constitutional disturbance, the temperature often reaching 101° or 102° F.

The treatment consists in applying a constriction band and making an incision over the centre of the most tender area, care being taken to avoid opening the tendon sheath lest the infection be conveyed to it. Moist dressings should be employed while the suppuration lasts. Carbolic fomentations, however, are to be avoided on account of the risk of inducing gangrene.

Whitlow of the Tendon Sheaths.—In this form the main incidence of the infection is on the sheaths of the flexor tendons, but it is not always possible to determine whether it started there or spread thither from the subcutaneous cellular tissue ([Fig. 9], d). In some cases both connective tissue planes are involved. The affected finger becomes red, painful, and swollen, the swelling spreading to the dorsum. The involvement of the tendon sheath is usually indicated by the patient being unable to flex the finger, and by the pain being increased when he attempts to do so. On account of the anatomical arrangement of the tendon sheaths, the process may spread into the forearm—directly in the case of the thumb and little finger, and after invading the palm in the case of the other fingers—and there give rise to a diffuse cellulitis which may result in sloughing of fasciæ and tendons. When the infection spreads into the common flexor sheath under the transverse carpal (anterior annular) ligament, it is not uncommon for the intercarpal and wrist joints to become implicated. Impaired movement of tendons and joints is, therefore, a common sequel to this variety of whitlow.

The treatment consists in inducing passive hyperæmia by Bier's method, and, if this is done early, suppuration may be avoided. If pus forms, small incisions are made, under local anæsthesia, to relieve the tension in the sheath and to diminish the risk of the tendons sloughing. No form of drain should be inserted. In the fingers the incisions should be made in the middle line, and in the palm they should be made over the metacarpal bones to avoid the digital vessels and nerves. If pus has spread under the transverse carpal ligament, the incision must be made above the wrist. Passive movements and massage must be commenced as early as possible and be perseveringly employed to diminish the formation of adhesions and resulting stiffness.

Subperiosteal Whitlow.—This form is usually an extension of the subcutaneous or of the thecal variety, but in some cases the inflammation begins in the periosteum—usually of the terminal phalanx. It may lead to necrosis of a portion or even of the entire phalanx. This is usually recognised by the persistence of suppuration long after the acute symptoms have passed off, and by feeling bare bone with the probe. In such cases one or more of the joints are usually implicated also, and lateral mobility and grating may be elicited. Recovery does not take place until the dead bone is removed, and the usefulness of the finger is often seriously impaired by fibrous or bony ankylosis of the interphalangeal joints. This may render amputation advisable when a stiff finger is likely to interfere with the patient's occupation.

Suppurative Cellulitis in Different Situations

Cellulitis of the forearm is usually a sequel to one of the deeper varieties of whitlow.

In the region of the elbow-joint, cellulitis is common around the olecranon. It may originate as an inflammation of the olecranon bursa, or may invade the bursa secondarily. In exceptional cases the elbow-joint is also involved.

Cellulitis of the axilla may originate in suppuration in the lymph glands, following an infected wound of the hand, or it may spread from a septic wound on the chest wall or in the neck. In some cases it is impossible to discover the primary seat of infection. A firm, brawny swelling forms in the armpit and extends on to the chest wall. It is attended with great pain, which is increased on moving the arm, and there is marked constitutional disturbance. When suppuration occurs, its spread is limited by the attachments of the axillary fascia, and the pus tends to burrow on to the chest wall beneath the pectoral muscles, and upwards towards the shoulder-joint, which may become infected. When the pus forms in the axillary space, the treatment consists in making free incisions, which should be placed on the thoracic side of the axilla to avoid the axillary vessels and nerves. If the pus spreads on to the chest wall, the abscess should be opened below the clavicle by Hilton's method, and a counter opening may be made in the axilla.