Pseudocheckerboard pattern: an interesting histopathological finding in mechanic's hands

Area of Science:

• Dermatopathology
• Dermatomyositis Research
• Histopathology

Background:

• Mechanic's hands, a dermatomyositis symptom, clinically resemble hand eczema.
• Typical histopathology includes hyperkeratosis, basal vacuolar changes, and necrotic keratinocytes.
• Comparative histopathologic studies are limited.

Observation:

• Histopathology of mechanic's hands (6 patients) was compared to palmoplantar eczema (27 patients).
• All mechanic's hands showed hyperkeratosis, basal vacuolar change, and necrotic keratinocytes.
• Basal vacuolar change was absent in palmoplantar eczema cases.

Findings:

• A pseudocheckerboard pattern was observed in the hyperkeratotic horny layer of three mechanic's hands cases.
• This pattern, featuring alternating parakeratosis and orthokeratosis, has not been previously emphasized for mechanic's hands.
• The pseudocheckerboard pattern was also found in four palmoplantar eczema cases.

Implications:

• The pseudocheckerboard pattern is not specific to mechanic's hands.
• However, this pattern may serve as a potential diagnostic clue for mechanic's hands in dermatomyositis.
• Further research can elucidate the diagnostic value of this histopathologic finding.