CD04: Linalool allergy presenting as lip swelling and tongue ulceration

Dushyanth Gnanappiragasam, Graham Johnston and Ingrid Helbling

University Hospitals of Leicester NHS Trust, Leicester, UK

We report a 12-year-old girl with a 2-year history of intermittent episodes of pruritic, flaky, erythematosus swelling of the eyelids and cheeks lasting up to 5 days. Initially symptoms only occurred when sitting on the floor during school assembly, which the family attributed to floor-cleaning products. She then noticed similar reactions in shops with scented candles, on exposure to air freshener at a friend’s house and with body spray in the school changing rooms. She then developed flares with a burning sensation following use of various cosmetic, toiletries and antiperspirant products containing essential oil and fragrances. She also developed a tingling and burning sensation of the mouth minutes after eating mango, pineapple, lemon, lime, peppermint, rosemary, cinnamon, parsley, chilli powder, turmeric and paprika. These evolved into erythematous ulcerated areas of the lips and tongue in the next 24–72 h. No breathing difficulties or gastrointestinal symptoms were reported. She had no past dermatological disease with no regular medications and no known allergies. There was no personal or family history of cold sores. The patient had not taken any prescribed or over-the-counter medications. At presentation she was using a Wash & Go shampoo, a Simple shampoo, Dove soap, a Simple facewash twice a day, wet wipes in the past and a lavender-containing yoga face mask. She also occasionally used a once-a-day sunscreen. Skin prick tests, including to aeroallergens, were negative. No prick tests to food allergens were undertaken. Full blood count, ferritin, vitamin D, renal and liver profile, C-reactive protein, antibody screen, mast cell tryptase and complement were all normal. Patch testing to the British Society for Cutaneous Allergy baseline series revealed a relevant 1+ positive reaction to linalool 0·1%. (pet.) She was also noted to be dermographic on dermographometer testing. It was thought that this girl had an allergic contact dermatitis reaction due to linalool either in direct skin/mucosal contact or airborne contact. The frequency of episodes was reported to have reduced on avoidance of perfumes and cosmetic products. The parents employed measures to minimize contact with linalool-containing foods. Adjustments such as washing the school desk in water rather than cleaning wipes and avoiding dance lessons with teakwood flooring has had a positive impact. Linalool is a terpene with low sensitizing potential. However, oxidation occurs upon air exposure, giving rise to the hydroperoxides, which are potent sensitizers. This case highlights the ubiquitous nature of linalool in products applied to the skin but also suggests that contact hypersensitivity to linalool can manifest as allergic contact stomatitis and mouth ulceration causing lip and tongue symptoms. We believe this is the first case of linalool exposure resulting in lip swelling and tongue ulceration.