Background

Symptomatic dermographism (SD) is the most common form of chronic inducible urticaria. The criterion standard for diagnosing SD and disease activity assessment in SD is provocation testing. As of now, if and what cofactors have an impact on provocation test results is unknown.

Objective

We sought to determine whether the induction of signs and symptoms of SD is affected by the intake of food.

Methods

We performed standardized skin provocation testing with a dermographometer (FricTest) before and after the intake of food. Patients were off antihistamine treatment for at least 3 days before testing. In total, 17 patients were tested after not having eaten for at least 4 hours (preprandial) on one volar forearm and 60 minutes after a carbohydrate-rich meal (postprandial) on the other. FricTest responses (wheals, itch) at trigger thresholds were assessed at 5 and 30 seconds as well as at 1, 2, 5, and 10 minutes.

Results

We identified 7 patients with SD who showed faster onset of FricTest-induced whealing and/or lower trigger thresholds after the intake of food, that is, food-exacerbated SD. In 5 other patients, FricTest provocation testing resulted in a positive response only after the intake of food, but not before. Three of these 5 patients with food-dependent SD had comorbid chronic spontaneous urticaria and 1 had cholinergic urticaria.

Conclusions

We describe 2 previously unknown subtypes of SD, food-exacerbated SD and food-dependent SD. The prevalence and underlying pathomechanisms of food-exacerbated SD and food-dependent SD need to be investigated, and the impact of food intake on other forms of chronic inducible urticaria should be explored.

中文翻译：

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食物依赖和食物加重的症状性皮肤病：症状性皮肤病的新变种

背景

症状性皮肤病（SD）是慢性诱发性荨麻疹最常见的形式。SD的诊断标准和SD中疾病活动性评估的标准是激发试验。截至目前，尚不清楚辅因子是否以及哪些因素对激发试验结果有影响。

客观的

我们试图确定 SD 体征和症状的诱发是否受到食物摄入的影响。

方法

我们在进食前后使用皮肤测量仪 (FricTest) 进行了标准化的皮肤刺激测试。患者在测试前停止抗组胺药治疗至少 3 天。总共有 17 名患者在一侧前臂至少 4 小时（餐前）没有进食，另一侧在富含碳水化合物的膳食（餐后）后 60 分钟后接受了测试。在 5 和 30 秒以及 1、2、5 和 10 分钟评估触发阈值处的 FricTest 反应（风团、瘙痒）。

结果

我们确定了 7 名 SD 患者，他们在进食后表现出更快的 FricTest 诱导的风化和/或更低的触发阈值，即食物加重的 SD。在另外 5 名患者中，FricTest 激发试验仅在进食后才产生阳性反应，但之前没有。这 5 名食物依赖型 SD 患者中有 3 名合并慢性自发性荨麻疹，1 名患有胆碱能性荨麻疹。

结论

我们描述了 2 种以前未知的 SD 亚型，即食物加重型 SD 和食物依赖性 SD。需要研究食物加重型 SD 和食物依赖型 SD 的患病率和潜在病理机制，并探讨食物摄入对其他形式的慢性诱发性荨麻疹的影响。