Chloasma.
What do you understand by chloasma?
Chloasma consists of an abnormal deposit of pigment, occurring as variously-sized and shaped, yellowish, brownish or blackish patches.
Describe the clinical appearances of chloasma.
Chloasma appears either in ill-defined patches, as is commonly the case, or as a diffuse discoloration. Its appearance is rapid or gradual, generally the latter. The patches are rounded or irregular, and usually shade off into the sound skin. One, several or more may be present, and coalescence may take place, resulting in a large irregular pigmented area. The color is yellowish, or brownish, and may even be 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 hyperæmia from scratching or any other cause, etc.
What cases of chloasma are included in the symptomatic group?