Tropical Medical Mystery Solved

I’ve always been fond of limes, particularly as a key part of a margarita or mohito. But on a recent cruise to the Caribbean my wife, Sandra, and I discovered that lime trees can pack a rather powerful punch.

Our cruise ship stopped for the day at Ocho Rios, Jamaica and we opted for a guided tour of a well known botanical garden and plantation. This first port on the cruise offered a chance to see some tropical flora and fauna in a delightful setting. During the tour our guide broke a leaf off a lime tree, crushed it slightly and passed it to Sandra. “Here”, he said, “smell this. The leaves have an aroma just like the fruit.” He was right. The sap had the texture of a lotion and the smell of fresh, ripe limes. It was so pleasant my wife rubbed some of the sap on the back of her left hand and thought nothing further of it. After the tour we went snorkeling and enjoyed the sunny and very warm climate.

The next day Sandra developed a very nasty looking red rash on her left hand. It reminded her of a bad sunburn but we discounted that because we always use sunscreen. We put some ice and lotion on the affected area and assumed it would soon fade. The next day the red skin developed ugly blisters, became swollen and very painful.

What could it be? We thought she might have come in contact with a jellyfish while snorkeling. But you can usually feel a jellyfish sting immediately and there was no indication of any along the beach we used.

A trip to the ship’s physician confirmed that there was a major problem with the skin on her left hand. The South African trained doctor had no idea what the cause was but he prescribed anti-inflammatory tablets and a soothing salve.

The next day the pain and blistering were even worse and the doctor continued his treatment with a hydrocortisone injection, pain pills and a special water-jell dressing. He advised keeping the hand elevated in a sling until the swelling subsided. There was still no diagnosis of the cause of the problem. My wife, a biologist, suggested the possibility of a connection between the lime leaf and the affliction but the doctor discounted the idea.

A week later, at the end of the cruise, we were back in Canada with a very sore, red hand (blisters the size of loonies) and plenty of questions about this strange affliction.

Because we still suspected a connection with the lime leaf episode, Sandra did a thorough Internet search and came up with the probable answer. She discovered a medical term with the long name: phytophotodermatitis.

Phytophotodermatitis, according to a medical website, is an ultraviolet-induced contact dermatitis due primarily to plant toxins. Lime juice (from leaves or fruit) contains phototoxins and, when combined with sunlight, can cause severe skin problems.

A trip to the local clinic confirmed the diagnosis. A doctor there was familiar with phytophotodermatitis and said she’d seen it occasionally in the south and with visitors to tropical climates. It was, she said, much like a severe second-degree burn and was a very serious injury.

The cruise ended a few weeks ago but the redness is still evident on my wife’s hand. The episode gives us new respect for the lowly lime. We will think of this experience when we toast our next travel adventure with a lime daiquiri.

By John Nowlan