Linear psoriasis following the typical distribution of the sciatic nerve

Area of Science:

• Dermatology
• Neurology
• Pathophysiology

Background:

• Emerging evidence suggests the nervous system influences psoriasis onset and flares.
• Factors like lesion symmetry, denervated skin sparing, and stress-induced lesions point to neurological involvement.

Observation:

• A 45-year-old male with plaque psoriasis developed a linear eruption along his sciatic nerve distribution.
• This coincided with lumbar disc herniation compressing L5-S1 nerve roots and causing sciatic pain.

Findings:

• Psoriasis lesions appeared in the exact distribution of sciatic nerve pain.
• The eruption resolved completely and spontaneously after the patient ceased activities that aggravated his back pain, relieving nerve compression.

Implications:

• This case suggests a novel correlation between lumbar nerve root compression and psoriasis onset.
• Local factors like TNF-alpha, neuropeptides, and nerve growth factor from nerve compression may trigger psoriasis in affected dermatomes.