These early syphilitic pains, in their violent aching character, and their intermittence, occasionally resemble true neuralgia very closely; but they are usually distinguished from it by their symmetrical disposition and by their attacking several bones at once. Moreover, they nearly always show the peculiarity of being distinctly aggravated by the warmth and repose of bed even if they be not altogether absent (as is not unfrequently the case) when the patient is up and moving about. A typical case of this kind is not so likely to be confounded with neuralgia as with rheumatism; but we occasionally meet with cases in which the pains are localized in a manner much more resembling the former. Thus I have met with several instances in which a patient, entirely unconscious (or professing to be unconscious) of having been syphilized, complained of violent pain in one tibia, recurring every night at a certain hour, and at first undistinguishable from that variety of sciatica in which the pain is principally felt in this situation, especially as it was relieved by firm pressure, just as neuralgia is in the early stages. And in one remarkable case, which came under my care at Westminster Hospital, the resemblance to clavus was most misleading:
H. A., aged nineteen, worker in a laundry, presented herself on account of a violent pain in the right parietal region, recurring three times daily with great regularity. The first two attacks occurred in the day-time, the third, which was always the severest, woke her out of sleep about midnight; the pain of this last was so agonizing that on more than one occasion she had become delirious. The girl (whose respectable appearance was against the notion of syphilis) was very anæmic; not, however, with the tint either of anæmic from hæmorrhage, or with that of chlorosis, exactly. It was rather a dirty sallowness of skin; but the gums and the conjunctivæ were exceedingly bloodless, and she complained of almost constant noises in the head. Menses scanty but regular. There was a soft anæmic bruit with the first sound at the base of the heart. Having failed to make any impression on the pains with iron and with muriate of ammonia in large doses, I was led to observe the fact that there was no diffuse soreness of the scalp, such as very commonly occurs in clavus, in the intervals of the pains, and the mere fact that there was this unusual circumstance in the case led me to reconsider the diagnosis thoroughly. In order to be sure of not omitting a point, I inquired, though without any expectation of an affirmative answer, as to the possibility of syphilitic disease; the girl at once confessed to having had sores, and examination detected a papular rash about the shoulders and back and on both thighs. Small doses of mercury greatly relieved the pain within a week, and cured it in less than three weeks; and it was very remarkable that the anæmia, which had obstinately refused to yield to iron, improved at once as the mercury began to relieve the pains. The eruption disappeared simultaneously.