Claverie F, Giordano-Labadie F, Bazex J
Service de Dermatologie, Vénéréologie et Allergologie, Hôpital de Purpan, Toulouse.
Ann Dermatol Venereol. 1997;124(4):315-7.
Contact dermatitis to propylene glycol, a widely used compound, is often difficult to evidence with skin tests.
We observed three cases of contact eczema to a dermal cream (Zovirax) used for labial herpes simplex. Patch-tests were positive in all three cases when the entire product was used but negative for each of the constituent components. The initial diagnosis could be an allergic reaction to the composition between the components as has been described elsewhere. Skin tests were completed with patch-tests using propylene glycol at concentrations over 5 p. 100 or with a vehicle other than vaseline (commercial tests use 5 p. 100 propylene glycol in vaseline). The results of these tests provided evidence allowing the diagnosis of contact dermatitis to the dermal cream due to allergic reaction to propylene glycol.
Our three cases illustrate the frequency of false negative reactions to propylene glycol on commercial patch-tests. In agreement with data in the literature, these tests show that propylene glycol must be used at concentrations up to 10 to 20 p. 100 to identify allergic reactions with patch-tests.
对广泛使用的化合物丙二醇发生的接触性皮炎，通过皮肤试验往往难以证实。
我们观察到3例对用于单纯性唇疱疹的一种皮肤乳膏（阿昔洛韦乳膏）发生接触性湿疹的病例。当使用整个产品进行斑贴试验时，所有3例均呈阳性，但对每种成分进行斑贴试验时均为阴性。初步诊断可能是如在其他地方所描述的对成分之间的组合物发生过敏反应。使用浓度超过5%（质量分数）的丙二醇或使用凡士林以外的赋形剂进行斑贴试验以完成皮肤试验（商业试验在凡士林中使用5%（质量分数）的丙二醇）。这些试验结果提供了证据，得以诊断因对丙二醇过敏反应而导致的对该皮肤乳膏的接触性皮炎。
我们的3例病例说明了商业斑贴试验中对丙二醇出现假阴性反应的频率。与文献中的数据一致，这些试验表明，必须使用浓度高达10%至20%（质量分数）的丙二醇进行斑贴试验以识别过敏反应。
