Lentigo(Synonym: Freckle.)
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.