A little baby was diagnosed with “phytophotodermatitis” by a doctor because of severe sunburn on both lower extremities caused by eating figs and taking a bath in water with fig leaves topically. What is “phytophotodermatitis”? What plants can cause this skin disease? Besides plants, can drugs cause “solar dermatitis”? What is the proper care and treatment in case of heliodermatitis? What is botanical solar dermatitis? Phytophotodermatitis is a dermatitis caused by the exposure of the body to certain photosensitive plants and then to certain wavelengths of light, resulting in redness, swelling, pain, rashes, blisters and other dermatitis symptoms, and is particularly likely to occur in people with allergies. It occurs with two necessary conditions: light and photosensitive plants. After eating photosensitive plants or skin contact with the juice of photosensitive plants, if there is no strong light exposure, it will not cause dermatitis; if there is strong light exposure, the photosensitive substances absorbed or adsorbed on the skin will react with sunlight, which in turn will cause redness and swelling of the exposed part of the skin, rashes, and then sun dermatitis. Which plants are photosensitive? These plants include cilantro, celery, fennel, parsley, etc., which have a strong smell; wild vegetables such as capers, amaranth and ashwagandha are also prone to solar dermatitis. In addition to the above-mentioned vegetables, certain fruits are also photosensitive, such as lemons and figs. These vegetables and fruits can cause solar dermatitis because they all contain the same ingredient – furanocoumarin, which is a natural photosensitizer, this ingredient itself does not cause damage to the skin, but when exposed to ultraviolet UVA radiation, it will produce a photosensitive reaction, which in turn leads to sunburn. This ingredient is also commonly found in commercially available citrus oils (such as lemon, orange, grapefruit, bergamot, tangerine, etc.), so care should be taken to avoid bright light exposure to the skin when using this type of oil. In addition to plants, the following drugs can also cause “solar dermatitis” Common photosensitizing drugs include: sulfonamide antibacterial drugs (such as cotrimoxazole), thiazide antihypertensive drugs (such as hydrochlorothiazide), tetracycline antibiotics (especially doxycycline), quinolone antibiotics (such as levofloxacin), non-steroidal anti-inflammatory painkillers (especially ketoprofen), phenothiazine antipsychotics (such as chlorpromazine) photosensitizer psoralen, antifungals ashwagandha and voriconazole, retinoids for seat sores, the antidepressant botanical St. John’s wort, and the botanical psoralen. When taking such photosensitive medications, I as a pharmacist would usually advise the patient to use them before bedtime if they are only taken once a day, such as retinoids. If they are taken multiple times a day, I would instruct the patient to avoid sun exposure as much as possible after taking the medication, and to pay attention to sun protection when going out as a last resort, such as wearing long-sleeved clothing and pants, wearing a wide-brimmed hat, wearing sunglasses, and applying sunscreen. What is the proper care and treatment in case of sunburn? Sunburns are usually divided into minor sunburns and severe sunburns. Skin care after a minor sunburn is similar to skin care after a minor burn. The main goal of treatment is to reduce further heat damage while treating the symptoms that manifest themselves accordingly. The first step is to avoid continued exposure to direct sunlight and to avoid photosensitive plants and medications; the second step is to help the skin dissipate heat by applying cold compresses. Cold compresses can be applied by wrapping a towel with crushed ice 3 to 4 times a day for 20 minutes each time, or by soaking the sunburned area in cold water, but not directly with ice. If cold compresses alone are not effective in relieving swelling and pain, you may choose to take oral ibuprofen for pain relief every 6-8 hours for 24-48 hours after the sunburn. If blisters are present, the blister area should be avoided from puncturing and can be gently washed and topically applied with mupirocin ointment twice a day to prevent infection. If the blister is inadvertently broken, it should be cleaned and disinfected and then topically applied with mupirocin ointment, followed by bandaging with sterile breathable gauze, not bandages with adhesive, etc., to avoid causing new damage to the sensitive skin after sunburn. Avoid applying topical hormonal ointments (such as Euthyrox, etc.) to sunburned skin. Although such ointments have the effect of reducing local redness, swelling, itching and pain, they are not conducive to the repair and healing of sunburned skin; ointments containing camphor or menthol (such as peppermint cream, etc.) should also be avoided within 24 hours after sunburn, as these ingredients may cause irritation to sunburned skin and also increase blood flow to the sunburned area leading to increased swelling and pain.