On the Chemical Nature of the Eczematogenic Agent in Oil of Turpentine, I

One hundred years of allergic contact dermatitis due to oxidized terpenes: What we can learn from old research on turpentine allergy

“…The Finnish group therefore wanted to study whether peroxide or other oxidation products could be specifically linked to the observed “eczematogenic” reactions. No peroxide was isolated but on the basis of the chemical and clinical knowledge obtained, the conclusions drawn were that the “eczematogenic” agent and α‐pinene peroxide are either identical or at least closely related substances 36 …”

“…No peroxide was isolated but on the basis of the chemical and clinical knowledge obtained, the conclusions drawn were that the "eczematogenic" agent and α-pinene peroxide are either identical or at least closely related substances. 36 After the Swedish publication stating that Δ 3 -carene hydroperoxides (Figure 2) should be the main culprit in turpentine from Scandinavia, 29 the group in Finland focused its efforts on carene considering that their results obtained on the autoxidation of α-pinene were due to contamination with Δ 3 -carene. 38 In their next study, 39 they compared the oxidation of Δ 3 -carene at room temperature with that of oxidation at 60 C and found that if the first takes several weeks or months, the increase in the temperature reduces the oxidation time to a few days.…”

“…24 The Finnish group found that a low concentration of α-pinene peroxide gave positive patch test reactions in individuals with known contact allergy to turpentine. 36 The discovery of a new analytic method called microadsorption, which utilizes displacement chromatography for polarity-based fractionation and measurement of refractive indices for identification, was crucial for the isolation of "eczematogenically" active substances from oxidized turpentine. [26][27][28][29][30] The fractionation of oxidized turpentine and various oxidized terpenes including Δ 3 -carene was combined with patch testing in only a single patient allergic to turpentine due to lack of materials, which was of course a drawback in this first investigation.…”

“…It was observed that Swedish and French turpentines gave positive reactions after oxidation, showing that Δ 3 ‐carene and the oxidation products of other substances caused skin sensitization 24 . The Finnish group found that a low concentration of α‐pinene peroxide gave positive patch test reactions in individuals with known contact allergy to turpentine 36 …”

“…The project was led by Dr Veikko Pirilä from the Institute of Occupational Health in Helsinki. The group began to investigate oil of turpentine before and after autoxidation based on the knowledge that oxidized terpenes can cause positive reactions in individual allergic to oil of turpentine 36. The research first confirmed that stored turpentine (source not specified) gave contact allergic reactions in patients with known allergy to turpentine at patch testing.…”