Department of Dermatology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Eur Acad Dermatol Venereol. 2013 Feb;27(2):e231-4. doi: 10.1111/j.1468-3083.2012.04561.x. Epub 2012 May 7.
Lichen planus (LP) is a common skin disorder of unknown aetiology that affects the skin, mucous membranes and nails. Although metal allergies have been implicated in the development of oral LP (OLP), the contribution of these allergies to nail LP (NLP) has yet to be studied in detail.
To elucidate the link between metal allergy and NLP.
We retrospectively analysed 115 LP patients with respect to the contribution of metals to either NLP or OLP. We also attempted to detect the specific metals involved in these nail lesions.
Of the 79 patients that received a metal patch test (PT), 24 (30%) were positive for at least one of the metal compounds tested. Notably, the prevalence of positive reactions to metals in the NLP patients was significantly higher as compared with the OLP patients (59% vs. 27%, P < 0.05). Among the 10 PT-positive patients with NLP, improvement of the skin lesions was seen in six of the patients after removal of dental materials containing causative metals or systemic disodium cromoglycate therapy. On the other hand, only 3 of 16 PT-positive patients with OLP exhibited improvement after the removal of dental materials. Causative metals in the dental fillings/braces were detected in the involved nail tissues.
This study suggests that metal allergies are more closely associated with NLP vs. OLP, and that deposited metals in the nail apparatus contribute to the development of lichenoid tissue reactions in the nail bed and matrix.
扁平苔藓（LP）是一种病因不明的常见皮肤疾病，影响皮肤、黏膜和指甲。虽然金属过敏已被认为与口腔扁平苔藓（OLP）的发生有关，但这些过敏对指甲扁平苔藓（NLP）的贡献尚未详细研究。
阐明金属过敏与 NLP 之间的联系。
我们回顾性分析了 115 例 LP 患者，分析金属对 NLP 或 OLP 的影响。我们还试图检测这些指甲病变中涉及的特定金属。
在接受金属斑贴试验（PT）的 79 例患者中，有 24 例（30%）对至少一种测试的金属化合物呈阳性反应。值得注意的是，NLP 患者对金属的阳性反应发生率明显高于 OLP 患者（59%比 27%，P<0.05）。在 10 例 NLP 阳性 PT 患者中，在去除含有致病金属的牙科材料或全身双钠色甘酸钠治疗后，有 6 例患者的皮肤病变得到改善。另一方面，在 16 例 OLP 阳性 PT 患者中，只有 3 例在去除牙科材料后病情改善。在受累指甲组织中检测到牙填充物/牙套中的致病金属。
本研究表明，金属过敏与 NLP 的相关性比 OLP 更密切，并且沉积在指甲装置中的金属有助于指甲床和基质中苔藓样组织反应的发生。
