What is a Lentigo?
What is a lentigo
A small, sharply circumscribed, pigmented macule surrounded by regular skin is a lentigo. A multiplicity of melanocytes is present in one spot giving pigment to this patch of skin. This hyperplasia of melanocytes is constricted to the cell layer directly above the basement membrane of the epidermis where melanocytes normally reside. This is what differentiates lentigines from moles since moles have a “nest” of melanocytes. Pigmentation on these lentigines can be uniform or variegated and can vary from brown to black colour. Lentigines can persist or erupt suddenly and disappear.
Why do they form?
There are several triggers and conditions which could cause a lentigo breakout in your body. These include:
- Overexposure to ultraviolet rays, especially if it is artificial
- Prolonged exposure to the sun
- Sunburns from childhood years
- Genetic mutations
- Light skin, blond hair, bright eye color
- Age and condition of the immune system
- Immunosuppression (recipients of organ donors and AIDS patients)
- Carriage of human papillomavirus
- Role of hormones (during puberty, pregnancy, and childbirth, as well as taking hormonal contraceptives)
- Indoor tanning
Types of Lentigines
Lentigines can grow singularly or in clusters. Most lentigines are smaller than 5 mm in diameter.
- Lentigines simplex: These are precursors to junctional naevus and arise during childhood and early adult life. They are present on the trunks and limbs and are small in size, brown in pigment and round or oval in shape. They are characterized by jagged or smooth edges and have a dry surface. They tend to disappear over time in most cases.
- Solar lentigines: These are a precursor to seborrhoeic keratosis. As the name suggests, solar lentigines are found on sites such as hands, face and lower legs which are overexposed to sunlight. They are yellow, light or dark brown in pigment and can be both, regular or irregular in shape. They too are dry to touch and have faded outlines. They gradually enlarge to several centimeters in diameter. Subsequently, disappear through the process of lichenoid keratosis.
- Inkspot lentigines or reticulated lentigines: These do not appear in large numbers. They develop after a light-skinned individual’s skin gets sunburned. They are dark brown to black in color and have irregular outlines.
- PUVA lentigines: These are similar to ink spot lentigines but develop on locations that have undergone photochemotherapy (PUVA) treatment.
- Tanning bed lentigines: These are similar to ink spot lentigines but form on parts of your body that have been subject to indoor tanning.
- Radiation lentigines: Radiation (accidental or therapeutic) can cause exposed body parts to form lentigines. These are generally associated with late-stage radiation dermatitis: epidermal atrophy, subcutaneous fibrosis, keratosis, telangiectasias.
- Melanotic macule: These form on mucosal surfaces or adjacent glabrous skin eg lip, vulva, penis and anus. They are light to dark brown in colour and are also called mucosal melanosis.
- Generalized lentigines: Found on children. Small macules tend to merge to form larger patches.
- Agminated lentigines: These are a naevoid eruption of lentigines confined to a single segmental area.
- Patterned lentigines: These are lentigines that inherently tend to develop on face, lips, buttocks, palms, and soles.
- Centrofacial neural dysraphic lentiginosis: These are associated with mental retardation.
- Lentiginosis syndromes: Syndromes include LEOPARD/Noonan, Peutz-Jeghers, Laugier-Hunziker, Moynahan, Xeroderma pigmentosum, myxoma syndromes, Ruvalcaba-Myhre-Smith, Bannayan-Zonnana syndrome, Cowden disease (multiple hamartoma syndrome ). The inheritance is autosomal dominant and sporadic cases are common. Widespread lentigines are present at birth or arise in early childhood. This syndrome is associated with neural, endocrine, and mesenchymal tumors.
Diseases Confused With Lentigo
Since lentigines are essentially pigmented patches on your skin, you could confuse them for other skin conditions when it is in its early stages:
- Freckles: They are light brown spots having a diameter of 3 mm which appear on the face, shoulders, and neck.
- Birthmark: These are congenital skin mark, which usually appears darker than the rest of the skin. The colors vary from wine, salmon to red (hemangioma).
- Moles(nevi): Pigmented spots of benign nature are named moles.
- Chloasma: Hyperpigmentation of an area of the skin due to an accelerated growth of melanocyte cells form chloasma.
Depending on the cause, lentigines appear on different parts of your body. They do not itch and could vary in colour from light brown to black. They are flat and have even or uneven edges.
In an attempt to lighten lentigines, the following applications can be used:
- SPF 50+ broad-spectrum sunscreen
- Hydroquinone bleaching cream
- Alpha hydroxy acids
- Lotions and creams with Vitamin C
- Azelaic acid
- Chemical peels
Several other treatments can be carried out that provide faster results, such as:
- Surgery: The tissue that is removed is slightly larger than the original lentigo so as to provide a safety zone. Prophylactic removal is conducted but without the regional lymph nodes being considered. In the case of metastases, regional lymph nodes are removed through radical resection.
- Perfusion: Inoperable malignizirovannogo lentigines on the limbs are treated this way. The blood flow is stopped with a tourniquet and the limb is administered cytotoxic agents (melphalan, dacarbazine – DTIC), which inhibit tumor growth. Perfusion is an apt method in cases which include multiple recurrences or metastases.
- Radiation therapy: Radiation is used as after surgical treatment and in the case of inoperable tumors. Radiation therapy is administered in large doses (500-600 R times a week).
- Chemo: Drugs such as bleomycin, vincristine, and lomustine are administered to the patient. They suppress the development of cancer cells in the lentigines.
- Glycosylated INF: This treatment deals with human interferon. There are no side effects. It is used in combination with other drugs to treat metastatic disease.
- Gene therapy: This vaccinates and immunizes individuals against the tumor.
- Cryotherapy and laser treatment: These are other alternatives to the aforementioned procedures.
The following methods should be adopted to prevent the formation of lentigines:
- Avoidance of prolonged exposure to the sun
- Reduction in the number of indoor tanning sessions
- Utilizing sunscreen at all times
- Adhering to a healthy lifestyle and maintaining a nutritious diet
Always consult a specialist before opting to undergo a treatment for a safe and personalized journey to healthy skin. Clearskin would love to diagnose and frame a treatment plan made especially for you and your needs.