Table 1.

Summary of the major points of discussion and answers in building an algorithm on LNP and the targeted topical use of 5% lidocaine-medicated plaster

I. What is the prevalence and etiology of LNP? Few data are present in the literature. Prevalence varies with the etiology, but it is generally estimated that about 60% of NP conditions are localized, and therefore identifiable as LNP.

II. Is there a diagnostic progression from the neuropathic pain grading system to the definition of LNP? A clear scientific rationale leads from the definition of NP to that of LNP. Thus, LNP should be considered a diagnostic refinement of NP (extensive definitions of NP and LNP are in the text).

III. Are the topography of pain and related signs and symptoms important in diagnosing LNP? The topographic definition of the symptomatic area is the first pivotal step in diagnosing LNP.

IV. How useful are questionnaires in diagnosing LNP? The diagnosis of NP and LNP does not rely on questionnaires, but it is recognized that they can be extremely useful for recording the quality and extent of the painful area.

V. Should symptom profiles be considered in diagnosing LNP? A recent effort has been made to establish which symptom profiles can be usefully applied to NP and LNP. Carefully recording them can help to establish a more targeted treatment.

VI. How can a minimum set of clinical and instrumental investigations be identified and what may be useful at the bedside in diagnosing LNP? A clinical neurological approach is mandatory. Bedside sensory testing is believed to be useful only after a thorough clinical examination and the formulation of a clinical hypothesis.

VII. Is there any algorithm that could be used to identify patients with LNP and could it be used to guide treatments? This paper proposes an easy-to-understand algorithm to identify patients with LNP and to guide targeted topical treatments.

VIII. What are the differences between topical and transdermal treatments? Topical treatments act locally. Transdermal treatments act by systemic absorption. Consequently, topical treatments do not have systemic side effects while transdermal treatments usually have the same side effects as when they are administered systemically.

IX. Can a topical treatment facilitate better adherence and compliance? Data confirm that topical treatments have better adherence and compliance, and this is also true for long-term treatment, in the elderly, and when combined with other medications. Up to three plasters are usually prescribed. More plasters are still considered safe, but compliance may be reduced.

X. What are the most frequent/relevant clinical presentations of LNP that can be treated with 5% lidocaine-medicated plaster? Generally, the more localized the pain (ie, the area of an A4 sheet) the better the results of topical treatment. Pathologies such as PHN, DN, and POP are the most widely studied.

Abbreviations: DN, diabetic neuropathy; LNP, localized neuropathic pain; NP, neuropathic pain; PHN, postherpetic neuralgia; POP, postoperative pain.