Warm summer months can provoke some unusual but recognizable rashes due to a combination of sun exposure and leisure activities. Imagine the following: You’ve recently had a weekend barbecue where the signature drink was the mojito – a concoction of rum, lime juice, mint leaves, and some other basic ingredients on ice. You’ve enjoyed this drink before without any problems – so why have you developed a painful rash on your hands after serving them to your friends at your backyard party? The answer lies in the combination of lime juice and the sun’s ultraviolet rays.
Phytophotodermatitis is the term used to describe the painful rash that develops when the skin is in contact with light-sensitive substances in the presence of ultraviolet light (UVA, specifically). Many different types of natural photosensitizing chemicals occur in plants, including psoralens or furocoumarins, and they absorb energy from ultraviolet light, causing certain changes in composition and energy state.
With direct contact, these chemical reactions can damage skin cell membranes, causing redness, pain, and blistering 24–48 hours after exposure to a photosensitizing agent. These are not individual allergic reactions – they can occur in anyone under the same circumstances. Exposure to lime juice alone, without ultraviolet light, will not have the same effect. Along with limes, some of the more common plants that produce a phytophotodermatitis include celery, parsnip, and fig leaves.
No specific treatment is required for phytophotodermatitis, but it is wise to understand the causes and avoid contact with reactive plant chemicals to prevent future reactions. In the case of particularly painful or inflamed skin, topical steroid creams from your doctor can be helpful to ease the discomfort. The skin may darken as it heals, producing a side effect known as post-inflammatory hyperpigmentation, which may last for short or longer periods depending upon the amount of natural pigment in the skin.
So feel free to continue enjoying those lime drinks this summer, but be aware of phytophotodermatitis – yet another reason to be conscious of sun exposure.
Last modified on July 2nd, 2019 at 6:59 pm