What are the characteristics of congenital dermal melanosis in terms of primary lesion, secondary change, color, size, shape, demarcation, configuration, distribution, and location?

From the Guidelines

Congenital dermal melanosis is characterized by a primary lesion that is a macule or patch, with secondary changes typically absent, a blue-gray to blue-green color, variable size, irregular shape with rounded borders, well-defined demarcation, and a solitary or multiple configuration, most commonly located in the lumbosacral region. The characteristics of congenital dermal melanosis can be described in detail using standard dermatological terminology.

• The primary lesion is a macule or patch with no palpable elevation or texture change, as seen in other congenital melanocytic nevi 1.
• Secondary changes are typically absent as these lesions don't evolve significantly over time.
• The color is characteristically blue-gray to blue-green, sometimes described as slate-like or having a bruise-like appearance, which is distinct from other types of congenital melanocytic nevi such as the "classic" or "blue" subtypes 1.
• Size varies widely, from a few centimeters to large areas covering significant portions of the body, similar to the variability seen in congenital melanocytic nevi 1.
• The shape is usually irregular with rounded borders.
• Demarcation is typically well-defined but may have slightly blurred edges that fade gradually into normal skin.
• Configuration is often solitary but can be multiple, sometimes coalescing into larger patches.
• Distribution is bilateral in about half of cases, and the most common location is the lumbosacral region (lower back and buttocks), though they can also appear on the shoulders, extremities, and rarely the face. These features result from melanocytes trapped deep in the dermis during embryonic development, causing Tyndall scattering of light that creates the characteristic blue coloration, as opposed to the melanocytes found in the epidermis and dermis in other congenital melanocytic nevi 1. Most lesions fade gradually during childhood, though some may persist into adulthood, highlighting the importance of continued monitoring, as recommended for congenital melanocytic nevi 1.

From the Research

Characteristics of Congenital Dermal Melanosis

• Primary Lesion: The primary lesion of congenital dermal melanosis is typically a macular blue-grey hyperpigmentation 2.
• Secondary Change: There is no specific information available on secondary changes in congenital dermal melanosis.
• Color: The color of congenital dermal melanosis is usually blue-grey 2 or speckled gray-blue 3.
• Size: The size of congenital dermal melanosis can vary, with some cases presenting as extensive lesions 3, 2.
• Shape: The shape of congenital dermal melanosis is not specifically described in the available studies.
• Demarcation: The demarcation of congenital dermal melanosis is typically well-defined, with a segmental pattern reported in some cases 3.
• Configuration: The configuration of congenital dermal melanosis can be macular or speckled 3, 2.
• Distribution: Congenital dermal melanosis can be distributed in a segmental pattern 3 or commonly observed in the lumbosacral region 2.
• Location: The location of congenital dermal melanosis can vary, with cases reported on the trunk 3 and lumbosacral region 2.