The Butyric Acid Test.—Noguchi discovered that the syphilitic antibody is precipitated with the globulin of the blood serum or cerebro spinal fluid and that the globulin content of these fluids is increased in syphilis. This increase in the globulin is found earlier than the presence of the antibody and can be detected in the early stages of primary syphilis before the antibody. The antibody in cases of latent syphilis is apt to be inconstant while the increase in the globulin is nearly always demonstrable. The cerebrospinal fluid can readily be obtained by lum bar puncture for this test.
The method of detecting an increase in the globulin content in the cerebrospinal fluid is extremely simple. Two parts of the fluid to be examined are mixed with five parts of a ten per cent butyric acid solu tion in physiological salt solution and the mixture boiled for a few min utes. One part of a normal sodic hydrate solution is then added and the whole boiled once more for a few seconds. The presence of an in creased amount of globulin is indicated by the appearance of a granular or flocculent precipitate which gradually settles to the bottom of the test tube. Normal cerebrospinal fluid shows only a slight cloudiness and turbidity hut no granular precipitate. The presence of blood in the cerebrospinal fluid renders the test valueless, so it is advisable when ob taining the spinal fluid to use two or three test tubes. The fluid to be used in the butyric acid test should be the last drawn.
The reaction appears more quickly and more distinctly the greater the amount of globulin present. Noguehi advises that the time period should not be greater than two hours before deciding whether the test is positive or negative.
He found the reaction appeared regularly in the cerebrospinal fluid of patients with syphilitic and parasyphilitic affections and also in all cases of meningitis from various causes. These acute inflammatory affections of the meninges are readily differentiated from syphilitic affections.
It is of the greatest prophylactic and therapeutic value to make the diagnosis of infantile syphilis as early as possible. If we knew t hat one of the parents of an apparently healthy newborn child was syphi litic, then we must observe the child carefully, so as not to overlook a possible specific infection. It must be remembered that infantile syph ilis may run its course without any skin eruption, and may be recog nized in practice only by a dry coryza, and a striking pallor, frequently combined with some enlargement of the liver and spleen.
Since, however, congenital syphilis is characterized in the great majority of cases by exanthemata, these must take a most prominent place in making a diagnosis. Since the individual skin lesions have been described before, it remains to discuss, at this point, the differential diagnosis between the syphilitic and nonsyphilitie dermatoses of infancy.
Syphilitic pemphigus neonatorum is distinguished from non syphilitic forms of pemphigus, aside from the predilection for the palms and soles, by its infiltrated base, and by the fact that the former is usually present at birth while the latter does not appear until a number of days after birth.
In distinguishing diffuse hereditary syphilitic skin infiltration in infancy from nonspecific diffuse inflammatory processes it is impor tart to remember that all erythematous lesions depending upon a mechanical, or chemical irritant show an intense, bright red color while that of the syphilitic dermatoses is a dull red with a brownish tint. The same difference is to be noted in making the differential diagnosis between syphilitic lesions and the diffuse reddening of the soles of the feet which is very frequent in atrophic infants and is dependent upon maceration. In the latter ease, too, the characteristic induration and the later desquamation is absent.
With reference to the differential diagnosis between eczema inter trigo and diffuse syphilitic skin infiltration, the following points must be kept in mind :—The syphilitic skin lesion never causes such a brilliant, inflammatory, red color as the intertriginous eczema. Whenever and wherever present the former has always a suggestion of a copper red, or a yellowish brown color, that the latter never has at any stage. One can always tell upon careful examination by the stiffness of the tissues when we pick up an affected fold of skin, whether or not there is present a firm infiltrate as is the case in diffuse skin syphilis. In intertrigo, it will be remembered, there is active hyperemia and swelling in the papillary layer and in the corium. These give the impression, however, to the palpating finger, of being soft and displaceable, and not of being a firm and unyielding infiltrate. The whole skin in the region of the mites and about the anus looks stiffer and smoother in the specific infiltration than in intertrigo, has a less brilliant color and does not have the swollen appearance of the intertriginous dermatitis. In the latter, too, espe cially in the genito-anal region one never sees at the height of the process any desquamation. Scaling could only occur when the acute inflamma tory redness and swelling have gone down, i.e., when the acute process has run its course and a restoration to the normal has nearly taken place. In diffuse skin syphilis of these regions, however, eroded and scaling areas may be situated side by side. It is a frequent occurrence to find the circumanal portion eroded but the skin of the nates them selves, dry, smooth, and scaling.