These nerve enlargements are at first tender but later become painless and we have extensive areas of anaesthesia and trophic changes of the skin and nails of fingers and toes such as felons, glazed skin, bullae, which latter on rupturing leave ulcers.
We also have absorption of the bones of the phalanges.
The phalangeal bones may be completely absorbed and a distorted nail cap the end of the metacarpal bone (lepra mutilans). Owing to the anaesthesia lepers often burn or injure their fingers and toes. Perforating ulcers are more common in leprosy than tabes.
Muscular palsies, atrophies and contractures are more common in the face and upper extremity than in the lower extremity. We may have changes quite similar to those of progressive muscular atrophy, the thenar and hypothenar, as well as the interossei, undergoing atrophy and resulting in the claw hand. There is extension of the first joint and flexion of the two distal joints of the fingers. Such hands may function quite well. Wrist-drop is not uncommon but foot-drop is rare. Rarely Charcot’s joint condition may be observed.
Of the facial muscles the orbicularis palpebrarum is most apt to show paralysis. The eyes are affected much less frequently in nerve leprosy than nodular, 45% as against 85% for nodular leprosy. The most common changes in nerve leprosy are ectropion of the lower lid and subsequent corneal ulceration.
Mixed Leprosy.—In mixed leprosy we simply have a combination of the manifestations of the two main types and as a matter of fact the majority of cases tend eventually to assume a mixed type.
Symptoms in Detail
Temperature Course.—On the whole leprosy runs an afebrile course except for the accessions of irregular fever at the time of the appearance of the successive crops of spots. This leprotic fever lasts for a few days or a week or so and then the course becomes afebrile. At such times sweating may be present and suggest malaria. In the final stages of leprosy the patient may run a high fever for long periods, associated with profuse sweating and loss of weight.
Skin.—The raised spots of nodular leprosy tend to come out in numbers on lobes of ears, over eyebrows and on cheeks, as well as backs of hands and forearms and on buttocks and feet. Soles of feet and palms of hands almost never show spots. In nerve leprosy the spots are often single and flat and often appear on parts of body covered by the clothing, as trunk, thighs or arms. The spots of leprosy are anaesthetic, often showing dissociation of sensation. The indurated spots of nodular leprosy are succeeded by tubercle-like growths. The hair falls out of the areas occupied by the spots.
Mucous Membranes.—The nasal mucosa is in particular studded with nodules which later undergo ulceration. An ulcer of the septum is often the first place from which leprosy bacilli may be obtained. The pharynx and larynx are also involved early.