Granuloma annulare with transfollicular perforation

Area of Science:

• Dermatology
• Pathology

Background:

• Transepithelial elimination is recognized as a common pathway in various skin disorders.
• Perforating dermatoses are characterized by transepidermal or transfollicular elimination of dermal material.

Observation:

• A unique case of papular granuloma annulare is presented.
• The pilary apparatus was observed to actively participate in the elimination of necrobiotic collagen from the dermis in one lesion.

Findings:

• This case represents the first documented instance of perforating granuloma annulare exhibiting a transfollicular elimination pathway.
• A novel classification of perforating dermatoses is proposed based on these observations.

Implications:

• This finding expands the understanding of the pathological mechanisms in granuloma annulare.
• The proposed classification may aid in the diagnosis and management of perforating dermatoses.