Fig. 38.—Primary Lesion on Thumb, with Secondary Eruption on Forearm.[1]
[1] From A System of Syphilis, vol. ii., edited by D'Arcy Power and J. Keogh Murphy, Oxford Medical Publications.
The Soft Sore, Soft Chancre, or Chancroid.—The differential diagnosis of syphilis necessitates the consideration of the soft sore, soft chancre, or chancroid, which is also a common form of venereal disease, and is due to infection with a virulent pus-forming bacillus, first described by Ducrey in 1889. Ducrey's bacillus occurs in the form of minute oval rods measuring about 1.5 µ in length, which stain readily with any basic aniline dye, but are quickly decolorised by Gram's method. They are found mixed with other organisms in the purulent discharge from the sore, and are chiefly arranged in small groups or in short chains. Soft sores are always contracted by direct contact from another individual, and the incubation period is a short one of from two to five days. They are usually situated in the vicinity of the frænum, and, in women, about the labia minora or fourchette; they probably originate in abrasions in these situations. They appear as pustules, which are rapidly converted into small, acutely inflamed ulcers with sharply cut, irregular margins, which bleed easily and yield an abundant yellow purulent discharge. They are devoid of the induration of syphilis, are painful, and nearly always multiple, reproducing themselves in successive crops by auto-inoculation. Soft sores are often complicated by phimosis and balanitis, and they frequently lead to infection of the glands in the groin. The resulting bubo is ill-defined, painful, and tender, and suppuration occurs in about one-fourth of the cases. The overlying skin becomes adherent and red, and suppuration takes place either in the form of separate foci in the interior of the individual glands, or around them; in the latter case, on incision, the glands are found lying bathed in pus. Ducrey's bacillus is found in pure culture in the pus. Sometimes other pyogenic organisms are superadded. After the bubo has been opened the wound may take on the characters of a soft sore.
Treatment.—Soft sores heal rapidly when kept clean. If concealed under a tight prepuce, an incision should be made along the dorsum to give access to the sores. They should be washed with eusol, and dusted with a mixture of one part iodoform and two parts boracic or salicylic acid, or, when the odour of iodoform is objected to, of equal parts of boracic acid and carbonate of zinc. Immersion of the penis in a bath of eusol for some hours daily is useful. The sore is then covered with a piece of gauze kept in position by drawing the prepuce over it, or by a few turns of a narrow bandage. Sublimed sulphur frequently rubbed into the sore is recommended by C. H. Mills. If the sores spread in spite of this, they should be painted with cocaine and then cauterised. When the glands in the groin are infected, the patient must be confined to bed, and a dressing impregnated with ichthyol and glycerin (10 per cent.) applied; the repeated use of a suction bell is of great service. Harrison recommends aspiration of a bubonic abscess, followed by injection of 1 in 20 solution of tincture of iodine into the cavity; this is in turn aspirated, and then 1 or 2 c.c. of the solution injected and left in. This is repeated as often as the cavity refills. It is sometimes necessary to let the pus out by one or more small incisions and continue the use of the suction bell.
Diagnosis of Primary Syphilis.—In cases in which there is a history of an incubation period of from three to five weeks, when the sore is indurated, persistent, and indolent, and attended with bullet-buboes in the groin, the diagnosis of primary syphilis is not difficult. Owing, however, to the great importance of instituting treatment at the earliest possible stage of the infection, an effort should be made to establish the diagnosis without delay by demonstrating the spirochæte. Before any antiseptic is applied, the margin of the suspected sore is rubbed with gauze, and the serum that exudes on pressure is collected in a capillary tube and sent to a pathologist for microscopical examination. A better specimen can sometimes be obtained by puncturing an enlarged lymph gland with a hypodermic needle, injecting a few minims of sterile saline solution and then aspirating the blood-stained fluid.
The Wassermann test must not be relied upon for diagnosis in the early stage, as it does not appear until the disease has become generalised and the secondary manifestations are about to begin. The practice of waiting in doubtful cases before making a diagnosis until secondary manifestations appear is to be condemned.
Extra-genital chancres, e.g. sores on the fingers of doctors or nurses, are specially liable to be overlooked, if the possibility of syphilis is not kept in mind.
It is important to bear in mind the possibility of a patient having acquired a mixed infection with the virus of soft chancre, which will manifest itself a few days after infection, and the virus of syphilis, which shows itself after an interval of several weeks. This occurrence was formerly the source of much confusion in diagnosis, and it was believed at one time that syphilis might result from soft sores, but it is now established that syphilis does not follow upon soft sores unless the virus of syphilis has been introduced at the same time. The practitioner must be on his guard, therefore, when a patient asks his advice concerning a venereal sore which has appeared within a few days of exposure to infection. Such a patient is naturally anxious to know whether he has contracted syphilis or not, but neither a positive nor a negative answer can be given—unless the spirochæte can be identified.