On the fourth day of our trip, we took a catamaran cruise to get a first hand view of the rocky coast that Cabo San Lucas is famous for. As we were lounging on the deck of this boat (wearing plenty of sunscreen and hats, of course) one of my friends asked me what the line under my chin was. I had no idea what she was talking about. I felt no pain or itching at all, and felt no abnormalities when I placed my fingers on the area she was referring to, so I thought nothing of it and carried on being mesmerized by the breathtaking sites.
When we returned from our day trip, I casually went to the bathroom to wash my face. Finally having the opportunity to see my face in a mirror, I noticed this red, scratch-like line going from the lower left corner of my lip to the underside of my chin. I stood there perplexed, thinking of when I could have possibly scratched or burned myself, or contracted ringworm. But there was no pain or itchiness which is almost always present with any of those conditions.
As the days moved closer to my trip coming to an end, this perfectly vertical line on my face began to swell a bit and showed signs of increased inflammation and blistering. There was still no pain or itchiness which just made me crazy with confusion. Here I am, an expert in aesthetics, and I have no idea what is on my face. Swelling and blistering is the trademark of phytophotodermatitis

I arrived back home in New York on a Sunday and immediately called the answering service of my dermatologist so that I could get an appointment as quickly as possible. When they called me back on Monday morning, they informed me that Tuesday morning was the next time they could squeeze me in.
I had several prospective student interviews scheduled that Monday, and did not think it would be good for business if the owner of the school had a distracting and perfectly vertical mystery line on her face. I solved the problem quickly by covering it up with some makeup and went on my way.
On Tuesday morning, I woke up with the excitement that only a fellow aesthetician could understand. I was going to see my dermatologist for a skin condition that I could not explain! Dr. Herbert Hochman, rated as one of New York Magazine's Top Doctors in the field of dermatology, saw me that Tuesday morning. When I informed him that I had just returned from Mexico, he told me that he knew exactly what the line was. I was giddy with excitement waiting to hear the diagnosis!
He told me that I had Berloque dermatitis! Nothing good comes after hearing those words. My excitement instantly turned into worry. I asked him what had happened to me. He asked me if I drank any margaritas in Mexico...
Dr. Hochman then proceeded to explain to me that somehow the lime juice from the cocktail dripped down my chin, and then before having the opportunity to clean my face, the juice was exposed to the strong sun and caused phytophotodermatitis. Phytophotodermatitis is a condition caused by a toxic reaction when certain plant chemicals put on the skin are exposed to sunlight (phyto=plant, and photo=light). Lime juice contains the chemical compound psoralen. Acccording to Science Daily, other plants such as celery root and parsley also contain psoralen. This condition is also colloquially called Bartender's dermatitis – for when a bartender at an outdoor function in the summer sun gets lime juice on his hands, he/she suffers a lime juice burn while preparing cocktails.
Dr. Christina Greenaway, who has published scientific papers on this subject, says that phytophotodermatitis can closely resemble contact dermatitis or a chemical burn. This can lead to a misdiagnosis if the dermatologist does not acquire a detailed history of the patient's recent activities.
Dr. Hochman told me a story about a young couple on honeymoon in the tropics. During a romantic beach visit, the new husband was gently caressing his wife's back. Unfortunately, he had just handled limes moments before rubbing his wife's back and they were still covered in juice. She was left with streak mark burns all over her back that lasted the duration of their trip.
When I returned home, I was so excited that I had this fascinating and fortunately harmless condition to share with my students and faculty. Since opening my school in 1985, I have always stressed the importance of using my own personal experiences as tools of learning. Phytophotodermatitis is "fashionably" known as Berloque dermatitis. When I was trained as an aromatherapist in London under the auspices of Eve Taylor and Michelin Arcier, I was taught of the dangers of the aromatherapy agent Bergamot Oil with regards to the skin. Bergamot Oil also contains psoralen and can therefore cause burns on the skin if exposed to sunlight. French women used to place Bergamot Oil on the underside of their pendants and then rest it against their chests. They would then remove the pendant and expose their chest to the sun. This would leave a burn on their chest in the exact shape of the pendant. This was seen as stylish in those times. "Berloque" is the French word for "pendant," which is where Berloque dermatitis is derived from.

My students and faculty were as captivated as I was about my condition. I was told by my doctor to apply prescription hydrocortisone for seven days every morning and evening. After seven days of treatment, the burn was still as red as ever. The doctor told me to continue the treatment for another week because sometimes it takes longer than a week to heal. In some cases, there can be temporary brown discoloration of the skin, after the burn goes away. If that were to occur, then I would have had to use a prescription hydroquinone as a bleaching agent. After about three weeks, the redness and swelling began to improve and eventually healed completely. I am not sure if I can say the same thing about my waist line. Improvement after three weeks of treatment

Annette Hanson is the President and Founder of Atelier Esthétique Institute, a New York State licensing aesthetic school, postgraduate facility, and the first accredited, internationally recognized U.S. member of ITEC in London. With 20 years experience as a noted expert and educator in skin care, Hanson was an early advocate for separate aesthetic licensing and was instrumental in the development of the 600-hour curriculum for the New York State Esthetics License as well as the written and practical exam. She serves as "Educator" on the Appearance Enhancement Advisory Committee for New York State.
www.aeinstitute.net