Relationship Between Serum Vitamin D Levels and Postherpetic Neuralgia.

Inclusion Criteria: * Age ≥18 years. * The patient was diagnosed with herpetic neuralgia and the course of disease was ≤3 months. * Can cooperate with the completion of inquiry and scale evaluation. Exclusion Criteria: * Severe spinal disease (fracture, malignancy, acute or chronic infection) confirmed by previous spinal surgery or imaging. * Previous history of head trauma. * Have autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, leucothrombocytopenia). * Suffering from mental disorders, intellectual disability, epilepsy and other diseases. * A history of substance abuse, drug abuse or alcohol abuse. * Pregnant or breastfeeding women. * And recent participation in other clinical studies.