Lemons

Limonene is a natural product found in essential oils and spices. Limonene is used as a flavoring and fragrance. It is also used in printing inks and in the paint and varnish industry. In a larger collective of epicutane-tested patients with a corresponding medical history, 5-0% showed a positive patch test reaction to oxidized limonene (test formulation: 0-3% in Vaseline) and 5-9% to oxidized linalool (1-0% in Vaseline). The substance can be found in the epicutaneous test series at: other fragrances; see below. Other fragrances (epicutaneous test series)

The DKG has so far tested the mixture dipentene, which consists of d-limonene and 1-limonene 2.0% in Vaseline. This form of application is no longer available as a test substance in Germany. In this respect, a 2% concentration of d-limonene in Vaseline is now recommended (as of 2016). A limitation of the diagnostic value is not to be expected, especially since the actual allergens are oxidation products of limonene.