Macbeth, Act 5, Scene 1. Lentigo monologue.
In truth, Lady Macbeth had it fairly easy. A little soap and water and her spot would theoretically be gone. The spot on her soul, however, is a more serious problem. Holy water would be just a start. In today’s post, we’ll address spots of a different color, or rather, multiple colors – lentigos.
What is a lentigo?
A lentigo (plural lentigines) is a small, pigmented flat or slightly raised spot with a clearly defined edge surrounded by normal-appearing skin. Lentigo or lentigines may appear suddenly or evolve slowly over years. They may occur anywhere on the body and vary in color from light tan to brown to black. Viewed under the microscope a lentigo shows an increased number of normal melanocytes, the skin cells that produce the pigment melanin that colors skin either genetically or as a result of exposure to UV light.
In a lentigo, melanocytes appear to replace keratinocytes in the basal layer of the epidermis. Lentigines are not the same as common skin moles (nevus, pl. nevi) in which melanocytes are found is “nests” or clusters. Although both nevi and lentigines are benign by nature, they must be carefully examined to differentiate them from early pigmented skin cancers such as melanomas.
What are the features of a lentigo?
Lentigines have been classified into many different types depending on what they look like, where they appear on the body, causative factors, and whether they are associated with other diseases or conditions.
Ink Spot Lentigo
Usually a single black spot among a number of solar lentigines.
Occur most commonly in patients of Celtic ancestry.’
Persistent, pale to dark brown flat spot appearing 6 months or longer after the start of PUVA (psoralen – UVA) therapy.
Similar in appearance to solar lentigines but lesions often have more irregular borders.
Similar to sun-induced lesions but often associated with signs of other long-term skin radiation damage such as epidermal atrophy, SC fibrosis, keratosis and telangiectasias. Does not appear to occur after local radiation therapy but from exposure to a large single dose of ionising radiation (e.g. exposure from the Chernobyl nuclear accident)
Tanning Bed Lentigo
Usually occurring in women with a history of tanning-bed use. Lesions may appear soon after exposure or they may appear after prolonged regular use of tanning beds.
Oral and labial melanotic macules
Also known as generalized lentigines and is characterized by numerous lentigines without signs of associaed conditions or triggering factors. The many small lesions may join together to form colored patches. Often involves the extremities, turnk, palms and genitalia.
What treatments are available?
Lentigines require no specific treatment. A broad-spectrum sunscreen may help to prevent further appearance and darkening of solar lentigines. Several creams may lighten lentigines if applied for a number of months. These include hydroquinone or antioxidants such as alpha hydroxyl acids, Vitamin C, and retinoids.
BFT authors, Drjohn and Drgeorge have documented improvements in lentigos (some outright disappear) with topically applied adult mesenchymal stem cell cytokines. We have some pictures we are gathering, and will append here. Our work in this field is continuing.