Mud bath dermatitis due to cinnamon oil.

A case of long-lasting, extensive eczematous and bullous dermatitis affecting exposed areas (arms and legs), beginning within 24 hr after having a mud bath with cinnamon essential oil in a spa, in a 74-year-old woman, is reported. Patch tests with the GEIDC standard battery and the dental battery (including clove essence and eugenol), cinnamon essence and its components were carried out 5 years later. Fragrance mix, cinnamon essence, eugenol, cinnamic alcohol and cinnamic aldehyde yielded a positive result. To our knowledge, this is the first case of cinnamon dermatitis after a mud bath.