Recalcitrant pustular eruptions of the extremities

Area of Science:

• Dermatology
• Histopathology

Background:

• Recalcitrant pustular eruptions on palms and soles present diagnostic challenges.
• Clinical sub-classifications include acrodermatitis continua, pustular psoriasis, and pustulosis palmaris et plantaris.

Purpose of the Study:

• To compare histological findings across three clinical sub-groups of pustular eruptions.
• To determine if histology alone can differentiate between these conditions.

Main Methods:

• Blind histological examination of 47 pustule biopsies.
• Comparison of findings among acrodermatitis continua, pustular psoriasis, and pustulosis palmaris et plantaris groups.

Main Results:

• Histology revealed uniform intra-epidermal, unilocular, well-delineated pustules in most cases.
• Histology alone could not reliably diagnose psoriasis in 44 out of 47 cases.
• No significant histological differences were observed among the three clinical subgroups.

Conclusions:

• The uniform histology and lack of clear differentiation suggest overlapping pathologies.
• The authors advocate for the descriptive term pustulosis palmaris et plantaris due to uncertain etiology and classification.
• Histopathology alone is insufficient for definitive diagnosis in these recalcitrant palmoplantar pustular conditions.