Chloasma uterinum is a well-recognized pigmentary disorder in gravid women, and may suggest an adrenal melasma. It affects the forehead, linea alba, and nipples more particularly, and passes off with the cause that induced it. The melasma of chronic uterine dis ease is of the same nature. Tubercular affections of the abdomen are very apt to determine melasma, and it has been noted in connec tion with hepatic cirrhosis and cancer of the stomach. It is only necessary to enumerate these conditions to place observers on their guard in determining the true nature of melasma in any given case.
It is not without interest, however, to note that in several of the conditions above mentioned the primary irritation or pigmentary excitant has its seat within the abdominal cavity, and we may note, further, in this connection the occurrence at times of darkening of the skin in chronic dysentery and in malarial poisoning, while the same condition may sometimes occur in cases of chronic pulmonary tuber culosis in which tubercles are ultimately developed in the intestines.
Syphilitic eruptions may often leave behind them permanent pig mentation, and that has sometimes led to unfounded suspicion of supra-renal melasma.
The occurrence of patches of parasitic pityriasis (tinea versicolor) in characteristic (covered) situations on the body could hardly be mistaken by any well-trained physician for the melasma now under consideration.
Attention must be directed to pigmentation due to long-continued dosage with arsenical preparations. It is curious how long this condition remained unobserved by physicians, and it is only within recent times that the fact of arsenical melasma has been certainly determined.
In cases of psoriasis, Hodgkin's disease, or of chorea, for exam ple, that have been vigorously treated with arsenic, it is not uncom mon to find the occurrence of bronzing and stains on the limbs and body.
This condition might well be mistaken at times for adrenal me lasma. It appears gradually to pass away after the drug has been withheld.
Variations in the depth of pigmentation in the course of a case of Addison's disease have been noted, so that the patient is sometimes darker and sometimes lighter.
The hair appears to undergo a deepening of hue, and sometimes becomes like that of dark races.
It must be noted that Addison's disease has frequently been met with where no melasma has ever been present.