Lichen Acid Mix

Lichen acid mix is a mixture of three chemicals that naturally occur in certain lichens:

• Atranorin

• Evernic acid

• Usnic acid

Lichens are plant-like organisms found on tree bark, leaves and soil, and produce various chemicals with aromatic and biocidal properties. Allergy to lichen components has been seen mostly with forestry and wood workers, or from use of perfumes that contain them.

Contact dermatitis from lichen acid mix components usually affects forestry workers and lichen pickers and appears on the hands, forearms, face, and other exposed areas. Allergy to lichens may also be observed following exposure to perfumes containing oak moss.

A history of abnormal photosensitivity seems to predispose to lichen-induced contact allergy. The general population may be exposed by burning lichen-infested logs in fireplaces.

Discontinuation of exposure to products containing lichen acid mix components should result in improvement and/or resolution of your dermatitis. By law, all products made in the U.S. for topical use have the ingredients listed either on the product package or the box that contains it, so check the labeling of your skin care products for one of these ingredients. If there is not enough information, ask your pharmacist or retailer, or contact the manufacturer directly. At work, request a Safety Data Sheet (SDS) to help identify potential sources of exposure.