In vivo reflectance confocal microscopy for evaluating common facial hyperpigmentation

Area of Science:

• Dermatology
• Medical Imaging
• Confocal Microscopy

Background:

• Facial hyperpigmentation, including nevus of Ota, acquired bilateral nevus of Ota-like macules (ABNOM), melasma, and café-au-lait spots, is often misdiagnosed in clinical settings.
• In vivo reflectance confocal microscopy (RCM) offers detailed visualization of skin structures.

Purpose of the Study:

• To summarize the in vivo reflectance confocal microscopy (RCM) features of common facial hyperpigmentation conditions.
• To assess the utility of RCM in differentiating ambiguous pigmented lesions.

Main Methods:

• 196 patients with facial hyperpigmentation (nevus of Ota, ABNOM, melasma, café-au-lait spots) were recruited.
• RCM imaging was performed on hyperpigmented areas and normal skin.
• RCM images were analyzed at the epidermis, dermal-epidermal junction (DEJ), and upper papillary dermis.

Main Results:

• Nevus of Ota and ABNOM showed similar RCM features: cord-like or lumpy structures in the superficial dermis.
• Melasma exhibited an increased cobblestone pattern in the epidermis and upper dermal changes.
• Café-au-lait spots displayed an increased cobblestone pattern in the epidermis and a regular, dense ringed pattern at the DEJ.

Conclusions:

• In vivo reflectance confocal microscopy (RCM) demonstrates distinct features for nevus of Ota, ABNOM, melasma, and café-au-lait spots.
• RCM can serve as an auxiliary diagnostic tool for these facial hyperpigmentation conditions.
• RCM imaging aids in the differential diagnosis of ambiguous pigmented facial lesions.