Part 51

#Describe lentigo.#

Lentigo, or freckle, is characterized by round or irregular, pin-head to pea-sized, yellowish, brownish or blackish spots, occurring usually about the face and the backs of the hands. It is a common affection, varying somewhat in the degree of development; the freckles present may be few and insignificant, or they may exist in profusion and be quite disfiguring. Heat and exposure favor their development. Those of light complexion, especially those with red hair, are its most common subjects. The color of the lesion is usually a yellowish-brown.

It is common to all ages, but is generally seen in its greatest development during adolescence, the disposition to its appearance becoming less marked as age advances.

#What is the pathology of lentigo?#

Lentigo consists simply of a circumscribed deposit of pigment granules--merely a localized increase of the normal pigment, differing from chloasma (q. v.) only in the size and shape of the pigmentation.

#State the prognosis.#

The blemishes can be removed by treatment, but their return is almost certain.

#Name the several applications commonly employed for their removal.#

An aqueous or alcoholic solution of corrosive sublimate, one-half to three grains to the ounce; lactic acid, one part to from six to twenty parts of water; and an ointment containing a drachm each of bismuth subnitrate and ammoniated mercury to the ounce.

The applications, which act by removing the epidermal and rete cells and with them the pigment, are made two or three times daily, and their use intermitted for a few days as soon as the skin becomes irritated or scaly.

Touching each freckle for a few seconds with the electric needle, just pricking the epidermis, will occasionally remove the blemish.

#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?#

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.