A 9-year-old male with no past medical history, brought in by his mother to the ER with a new rash on his face and torso. The rash began 10 days ago. On the day he developed the rash, the patient noted swimming in a newly chlorinated outdoor pool. That same day he also played with freshly picked oranges and limes outdoors with his friends, having squeezed the juices onto his head and body. He developed a non-painful, non-pruritic, hyper-pigmented rash on his left cheek.
Over the course of 3 days, the patient and his family went on a trip to a local river, during which the rash evolved to scattered patches on his face and dorsum of his hands with an associated burning sensation exacerbated by contact with hot water or sunscreen. He received outpatient treated by a medical provider at day 3 for presumed infection with both oral and topical antibiotics. He completed the antibiotics, with worsening of his skin lesions. They have since formed blisters and affected his torso.
The patient never had any similar symptoms, or allergies. He had no sick contacts or travel outside the U.S. He denies any history of trauma, thermal burns, or arthropod exposure. The patient has not had fevers, respiratory symptoms, gastrointestinal symptoms, or urinary symptoms.
Vitals: T 97.3 F; HR 86; RR 18; O2 sat 100%; BP 109/67
General: Well-appearing child, appropriately developed for his age, in no acute distress
Skin: Multiple non-purulent lesions in different phases of healing. There are a few non-tender hyper-pigmented lesions over his face. There are linear hyper-pigmented lesions over his chest wall. He has tender lesions to the epigastric region and left flank, with healing pink denuded central areas, some with a linear appearance and a few scabbed lesions. There were no intact bullae or vesicles, and no mucosal involvement.
Sunlight and juices from citrus fruits
Phytophotodermatitis is a cutaneous photo-toxic inflammatory reaction resulting from skin exposure to furocoumarins from particular foods and plants, followed by sun exposure to the exposed skin. Furocoumarins are found in commons foods such as celery, lemons, and limes. These chemicals undergo a chemical reaction when exposed to ultraviolet light. The presence of this reaction on one’s skin during sun exposures leads to the local reaction to photosensitized skin, similar to a burn.
In the above case, the patient was exposed to both lime and orange juice followed by sun exposure. The rash typically occurs within 1-2 days after the precipitating event, and is sharply demarcated to the areas of both chemical and ultraviolet light exposure. The reactions frequently appear as linear erythematous patches and plaques. They can be edematous, bullous, or vesicular. Patients will often complain of a burning pain to the affected area, exacerbated by heat and moisture. A characteristic late finding is a post-inflammatory hyperpigmentation that may last for months to years after the initial exposure. The reaction is not an allergic or immune-mediated response. As such, no prior exposure is necessary to develop a reaction.
Take Home Points
- Phytophotodermatitis can often be mistaken for non-accidental trauma as it can mimic burns or wounds in different stages of healing. It can sometimes take the form of hand-prints or splash/spills, depending on the nature of the exposure.
- This condition is benign and self-limited. It will resolve with supportive care including:
- Moist dressings
- Local wound care
- NSAIDs for pain