Understanding Lentigines: Types, Diagnosis, and Management

Lentigines are benign pigmented spots on the skin caused by increased activity of melanocytes, the cells responsible for pigment production. Unlike freckles (ephelides), which often lighten or disappear with reduced sun exposure, lentigines persist year-round. These lesions can serve as indicators of skin aging or sun damage. Let's explore the different types of lentigines, their distinguishing features, and available treatments.

Types of Lentigines

Lentigines can be broadly categorized into two main types: simple lentigines and solar lentigines. Additionally, a specific form of simple lentigo, the mucosal melanotic macule, develops on mucosal surfaces such as the lips or genitalia.

1. Simple Lentigo

Simple lentigines often appear during childhood as small, sharply defined, uniformly pigmented macules. These lesions are typically less than 5 mm in diameter and can appear on any part of the body, irrespective of sun exposure. They are usually isolated but may be linked to certain syndromes or conditions, such as Addison’s disease, which can cause an increase in their number or darkening due to elevated levels of adrenocorticotropic hormone (ACTH).

Mucosal melanotic macule, a subtype, predominantly affects the vermilion border of the lower lip. It commonly presents in White adolescent girls and young women but can also appear on the oral or genital mucosa. These macules are usually solitary but may occur in clusters in certain genetic conditions, including Peutz-Jeghers and Bannayan-Riley-Ruvalcaba syndromes.

2. Solar Lentigo

Solar lentigines, often called age spots or sunspots, develop in sun-exposed areas such as the face, hands, shoulders, and upper back. They tend to appear in adulthood due to cumulative UV exposure but can also occur in children with lighter skin tones who experience frequent sunburns. These macules are typically larger than freckles and have irregular borders.

Conditions like xeroderma pigmentosum, a genetic disorder characterized by extreme sensitivity to UV light, can cause solar lentigines to appear at an unusually young age. Large and irregular solar lentigines are also common in individuals with oculocutaneous albinism type 2.

Diagnosis and Differential Considerations

The clinical diagnosis of lentigines often involves distinguishing them from other pigmented lesions such as melanocytic nevi (moles), seborrheic keratoses, or, in rarer cases, lentigo maligna, a precursor to melanoma.

In mucosal lentigines with irregular pigmentation, dermoscopic evaluation is often helpful, revealing patterns consistent with benign lesions. However, if there's diagnostic uncertainty, especially for genital or atypically pigmented macules, a biopsy might be performed to rule out melanoma.

Management and Treatment

While lentigines are benign and pose no direct health risk, they may be of cosmetic concern. Treatment options include:

Cryotherapy: Freezing the lesions with liquid nitrogen to induce peeling.
Laser Therapy: Various lasers, including Q-switched ruby and picosecond lasers, target melanin to lighten the spots.
Intense Pulsed Light (IPL): Broad-spectrum light therapy for reducing pigmentation.

Although solar lentigines themselves are harmless, their presence signifies significant sun damage and an elevated risk for skin cancers like melanoma, basal cell carcinoma, and squamous cell carcinoma. Routine skin checks are essential, especially for individuals with a family history of melanoma or numerous atypical moles. Dermatologists recommend regular sun protection to prevent new lesions and minimize further photodamage.

Final Thoughts

Lentigines, though benign, are a visible marker of skin health and aging. Proper diagnosis, preventative measures, and treatment options like ENTIGO—a leading approach in pigmentation management—can help individuals address these concerns while maintaining overall skin wellness. Regular dermatological assessments ensure early detection of more serious conditions, reinforcing the importance of skin care at every stage of life.