Lichen planus may be mistaken for papular syphilide, but may be distinguished from it by intense itching and by lack of the pigment changes which characterize the syphilide.
The squamous syphilide is sometimes a continuance of the papular, and sometimes it begins as such. It is characterized by a variety of scaly macules and papules, which strikingly resemble the lesions of psoriasis. The latter are seldom seen on the palms and soles, while the squamous syphilide is very frequently seen in these locations. Moreover, along with the squamous lesions are frequently associated other skin lesions, which give the case a complex type, resembling at one point one of the non-specific affections, and others at other points. Such changes are mainly expressions of various stages in the involution or degeneration of the papule, but they may give the case a variegated appearance, in which pigmentation may be prominent.
Some years ago Biett described a form of syphilide which he claimed was unmistakable and indicative. Since he described the lesion it has been known as Biett’s collarette. It appears in from ten to twenty weeks after the secondary symptoms are fully declared, is superficial, usually situated upon the trunk and extremities, but never upon the palms or soles. It consists of a flat papule almost level with the skin, 1 to 2 Cm. in diameter, rounded in contour, while around it there is seen a zone of white epidermal scales pretty sharply defined and giving it the name of collarette. The area within is dry and painless, and the ring itself narrow. There is little or no itching. It may be followed by some other skin lesion. The lesion is often so mild as to pass unnoticed.
At other times pustulocrustaceous syphilides will appear above the level of the skin, surrounded by a series of narrow concentric rings, not scaly, but composed of a number of small pustules, the first ring being perhaps an inch from the centre of the inner lesion. This is seen more often in males than in females, and it seems as though the smaller pustules were the result of an auto-infection of ordinary pyogenic character. In the presence of either of these lesions a positive diagnosis of syphilis can be made.
The pustular syphilide may give rise to large or small pustules, which soon become superficial ulcers, often irregular in shape, with an unhealthy floor which may be livid or gangrenous, or may resemble a diphtheritic lesion, while from its surface exudes a mixture of blood, debris, and pus, which dries into dark-colored crusts and constitutes the lesion known as ecthyma. These lesions are often deceptive, since while scabbing seems to be occurring over the surface the ulceration may be extending beneath. This is an intermediate or earlier tertiary rather than a secondary lesion.
Another type of pustular syphilide is that known as rupia, where the ulcers are larger and are covered with concentric layers of crust resembling an oyster-shell. These lesions begin as papules and undergo changes which make them bullæ or pustules and then open ulcers. The peculiar scabs are somewhat conical in shape when not disturbed, and are greenish or brownish in color. If they are dislodged, irregular, indolent, and often sensitive ulcerated areas will be found beneath them. Even when these ulcers heal they are irregular in outline and show a white scar often surrounded by an areola of pigment. This rupia is the most visible lesion of syphilis, as no other skin disease assumes any such type.
In the last-described and ulcerative forms of syphilide there is a possibility of septic infection, or at least of septic intoxication by absorption; hence the need for care in this direction. In fact, into the treatment of every pustular indication of syphilis the elements of local protection and local antisepsis should enter.
The Mucous Membranes.
—Here the manifestations of syphilis are of great importance because of their extreme infectiousness. The earlier manifestations are seen mainly about the mouth. When an eruption appears upon the skin a condition corresponding to it may often be recognized in the pharynx and upon the uvula and soft palate. This will be accompanied by discomfort, and the patient complains of “soreness of the throat.” These throat lesions are chronic, liable to recur, and disappear slowly, unless the patient is vigorously treated; they sometimes cause dryness of the fauces, followed by a free flow of mucus. The dusky discoloration of the rash is quite distinctive.
The congested areas have a dusky hue on the skin and are spoken of as “coppery” or “raw-ham” in tint. They are usually well outlined; should the disease progress they become eroded. “Syphilitic sore throat,” as this condition is often called, may be aggravated by the use of tobacco and by unclean mouths. The involvement of the cervical lymphatics will be proportionate to the vividness of the lesion.