Histopathologic findings characteristic of CARD14-associated papulosquamous eruption

Area of Science:

• Dermatopathology
• Genetics
• Immunodermatology

Background:

• CARD14 mutations cause a rare papulosquamous eruption.
• This condition shares features with psoriasis and pityriasis rubra pilaris.
• Distinguishing histopathologic features are crucial for diagnosis.

Purpose of the Study:

• To identify and describe the unique histopathologic features of CARD14-associated papulosquamous eruption.
• To aid in the differential diagnosis of papulosquamous disorders.

Main Methods:

• Retrospective analysis of lesional skin biopsies.
• Comparison of histopathologic findings in CARD14-associated eruption, plaque psoriasis, and pityriasis rubra pilaris.

Main Results:

• Consistent findings in CARD14-associated eruption include alternating parakeratosis and orthokeratosis (checkerboard pattern).
• Acanthosis without acantholysis and dilated dermal papillary vessels were observed.
• Follicular plugging was present in some cases.

Conclusions:

• CARD14-associated papulosquamous eruption exhibits a distinct histopathologic profile.
• The findings often overlap with, but can be distinguished from, psoriasis and pityriasis rubra pilaris.
• A predominance of pityriasis rubra pilaris-like features was noted.