Changes are frequently found in the skin, yet since they are neither constant nor specific to this disease, they possess less of a diagnostic than of a general pathologic interest.
We have already described in another section the vasomotor disturbances manifested during the different stages of the paroxysm. We may mention further that an evident hyperalgesia of the skin is not uncommon during a paroxysm. I have observed it frequently on pricking the finger or the lobe of the ear for the purpose of examining the blood.
The exanthemata are more important. During an acute infection, herpes is frequent. This usually occurs on the nose, the lips, " or the cheeks, although sometimes, too, on other places. Laveran mentions a case of herpes of the soft palate; I saw once a herpes of the left hand. Kelsch and Kiener maintain that it accompanied one third of the cases of "bilious gastric" malaria . They observed it even on the hairy scalp. Yet F. Plehn saw, among 714 cases of West African fever, only one case of herpes.
In about the same frequency as herpes, urticaria is observed. This occurs sometimes with the paroxysms, sometimes independently of them. According to Kelsch and Kiener's experience, it seems to occur especially in grave cases. Erythema is less frequent, and . appears in spots or may be distributed over the whole body. In children a peculiar form of erythema nodosum sometimes occurs (Obedenaire, Boicesco, and Moncorvo). This is manifested by quite prominent, painful nodes situated on the arms and legs. They are dark red in color, especially during the paroxysms, and pass away without suppuration. Such an erythema can be regarded as only part of the disease picture, when no drugs have been previously administered which might produce such a condition (quinin, antipyrin, etc.).
* Latschenberger observed pigment granules in the circulating blood of guinea pigs and frogs, as well as other species of animals, the blood of which contains hemoglobin I cannot say whether or not these occur physiologically in human blood, yet there is no reason for confusing them with melanin, if my rule is followed to consider as positive only the pigment found in leukocytes.
Roseola is a very rare symptom of malaria , and one I have personally never observed. Purpura has been seen in rare cases. The opinion of some writers that herpes zoster is connected with malaria seems to me unfounded (Winfield affirms that he found malarial parasites in 8 cases of zoster [?] ).
After the disease has continued a long time the skin becomes strikingly pale, and takes on an ashen gray to light yellow color. This is the well known color of the malarial cachectic. The discoloration is always diffuse, even though here and there the skin may be somewhat speckled as a result of the unequal distribution of the pigment. The mucous membrane assumes also a diffuse grayish or light yellowish color, without showing the pigmentation peculiar to Addison's disease.
A more evident yellowish color-in other words, icterus-is not rare. When it occurs, it is usually slight, though it may be marked. This icterus of acute malaria is the so called "urobilin icterus," since the urine contains only urobilin and not bilirubin.
Edema of the lower extremities sometimes occurs after malarial infections, or even during them, when the patient does not take to bed.
Anthrax, erysipelas, phlegmon, and noma sometimes complicate the severe forms, and are naturally to be regarded as secondary infections. Gangrene of varying extent and distribution is not rarely observed after severe infections.