Inverted follicular keratosis: dermoscopic and reflectance confocal microscopic features

Area of Science:

• Dermatology
• Dermoscopy
• Confocal Microscopy

Background:

• Inverted follicular keratosis (IFK) is a rare benign facial neoplasm.
• Clinical differentiation of IFK from other facial lesions is challenging.
• Established dermoscopic criteria for IFK are lacking.

Observation:

• This study presents the dermoscopic findings in four IFK cases.
• Common features included peripheral hairpin vessels with a whitish halo and central amorphous areas.
• Reflectance confocal microscopy revealed specific epidermal and vascular patterns.

Findings:

• Three cases showed radial peripheral hairpin vessels, whitish halos, and central white-yellowish amorphous areas.
• One case exhibited glomerular vessels centrally.
• The fourth case displayed arborizing vessels within a central white amorphous area.

Implications:

• Dermoscopy offers valuable diagnostic clues for inverted follicular keratosis.
• This is the first case series detailing IFK dermoscopic features.
• Confocal microscopy provides further insights into IFK's microscopic structure.