Methods	RCT, DB, parallel study, 6 week duration 7 day washout for topical medications, current oral medication continued with no changes to dose or frequency Pain assessment at 0, 2, 4 and 6 weeks
Participants	Chronic severe postherpetic neuralgia (at least 12 months duration). Pain poorly or incompletely controlled with oral analgesics, antidepressants and neuroleptic agents Mean age 72 years (range 54 to 90) N = 32 M = 12, F = 20 Mean baseline pain >70 mm
Interventions	Capsaicin 0.075% cream, n = 16 Vehicle cream, n = 16 Cream applied to painful areas × 3 to × 4 daily
Outcomes	PI: standard 5 point scale and 100 mm VAS PR: 100 mm VAS Adverse events Withdrawals
Notes	Oxford Quality Score: R2, DB2, W0 OPVS 14/16
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	computer-generated randomisation schedule
Allocation concealment?	Unclear	not described
Blinding? All outcomes	Yes	“identical appearing”