blackish
(_melasma_, _melanoderma_). The skin is otherwise normal. The face is the
most common site.

#Into what two general classes may the various examples of chloasma be
grouped?#

Idiopathic and symptomatic.

#What cases of chloasma are included in the idiopathic group?#

All those cases of pigmentation caused by external agents, such as the
sun's rays, sinapisms, blisters, continued cutaneous hyperaemia from
scratching or any other cause, etc.

#What cases of chloasma are included in the symptomatic group?#

All forms of pigment deposit which occur as a consequence of various
organic and systemic diseases, as the pigmentation, for instance, seen
in association with tuberculosis, cancer, malaria, Addison's disease,
uterine affections, and the like. In such cases, with few exceptions,
the pigmentation is usually more or less diffuse.

#What is chloasma uterinum?#

Chloasma uterinum is a term applied to the ill-defined patches of
yellowish-brown pigmentation appearing upon the faces of women, usually
between the ages of twenty-five and fifty. It is most commonly seen
during pregnancy, but may occur in connection with any functional or
organic disease of the utero-ovarian apparatus.

#What is argyria?#

Argyria is the term applied to the slate-like discoloration which
follows the prolonged administration of silver nitrate.

#State the pathology of chloasma.#

The sole change consists in an increased deposit of pigment.

#Give the prognosis of chloasma.#

Unless a removal of the exciting or predisposing cause is possible, the
prognosis is, as a rule, unfavorable, and the relief furnished by local
applications usually but temporary.

#If constitutional treatment is advisable, upon what is it to be based?#

Upon general principles; there are no special remedies.

#How do external remedies act?#

Mainly by removing the rete cells and with them the pigmentation; and
partly, also, by stimulating the absorbents.

#Are all external remedies which tend to remove the upper layers of the
skin equally useful for this purpose?#

No; on the contrary some such applications are followed by an increase
in the pigment deposit.

#Name the several applications commonly employed.#

Corrosive sublimate in solution, in the strength of one to four grains
to the ounce of alcohol and water; a lotion made up as follows:--

[Rx] Hydrargyri chlorid. corros., ......... gr. iij-viij
Ac. a