Table 3 Secondary outcomes

→ Variation of the primary outcome (averaged pain intensity)

→ Frequency of pain attacks per day

→ Pain intensity:

   ▪ Pain at rest

   ▪ Pain attack

→ Time to symptom alleviation

→ Analgesic demand

→ Side effects of the therapy

→ Standardised pain questionnaires

   ▪ Neuropathic Pain questionnaire (NPI)

   ▪ Quality of life (SF 36)

   ▪ Pain Disability Index (PDI)

   ▪ Pain description acc. to Geissner (SES)

   ▪ Pain discomfort list acc. to van Zerssen

→ Quantitative sensory testing (QST):

   ▪ thermic sensation:

▪ cold and warm detection threshold (CDT + WDT)

▪ thermic difference threshold (TSL)

▪ cold and heat pain threshold (CPT + HPT)

   ▪ tactile detection threshold

   ▪ mechanical pain threshold

   ▪ mechanical pain intensity

   ▪ mechanical allodynia

   ▪ wind up phenomenon

   ▪ vibration threshold

   ▪ pressure pain threshold

→ Change of rash before and after treatment

→ Incidence of postherpetic neuralgia 6 month after treatment

→ Credibility

→ Cost effectiveness

→ Side effects