Source: FM93 Voice of Traffic
Summer is coming, and sun protection has become a compulsory course for beauty ladies. However, in the Department of Dermatology of Ningbo First Hospital, since May, more than 100 patients have been treated for solar dermatitis.
Doctors remind you that after taking certain medicines and foods, pay special attention to avoiding the sun!
Exposure to the sun for 2 hours after medication
The woman had erythema all over her body
"Just basking in the sun, how come I have a rash all over my body, why am I so weak?" Ms. Han, a citizen, is 30 years old this year, and she recently came to the City First Hospital for treatment because of a rash all over her body.
The day before her visit, she spent two hours outdoors at noon without sun protection. When she got home that day, she felt an itch on her legs and saw a lump of red spots on her legs. The next day, there were more and more red spots, all over her body, and she felt that her whole body was itchy.
"Doctor, it's not the first time I've been so tanned, I used to tan a little bit, how can this be now?" The doctor carefully inquired about Ms. Han's life and found that she was injecting the drug moxifloxacin because of pneumonia.
At the professional pharmacist clinic, after the pharmacist learned about the drugs ms. Han used, he suspected that it was sunlight dermatitis caused by the photosensitivity reaction caused by moxifloxacin, and suggested that the doctor first stop moxifloxacin for her and give her anti-allergic drugs. Sure enough, her symptoms eased on the first day of medication, and after 4 days, all the erythema subsided.
Dermatitis caused by exposure to the sun after medication
It can happen in a few minutes at the earliest
Zhu Suyan, deputy pharmacist of the Department of Pharmacy of the First Hospital of Ningbo, introduced that solar dermatitis is a common skin disease in summer, commonly known as sunburn or ultraviolet allergy. If the sun exposure area is extensive, a small number of patients may also develop systemic symptoms such as fever and fatigue. In general, in late spring and early summer, children, women, skiers and water surface workers, and people who have been engaged in outdoor labor for a long time are prone to seizures.
"The occurrence of solar dermatitis is related to the intensity of light, the time of irradiation, the color of individual skin, physique, race, etc. In addition, some photosensitive drugs and foods can also induce solar dermatitis. Zhu Suyan said that the photosensitivity reaction of the drug is divided into phototoxic reactions and photoallergic reactions.
Phototoxic reactions mainly occur in systemic medication, can occur in anyone, generally after the first medication by sunlight and similar light sources, a few minutes to a few hours can occur, the onset of the face, chest V-shaped area, limbs and other exposed parts of the skin, like Ms. Han belongs to this reaction.
Photoallergic reactions can be induced by topical and systemic medications, occurring in a small number of allergic patients, and may occur with small doses of light-sensitive drugs and weak sunlight exposure.
A variety of drugs and foods can produce photosensitivity reactions
Be careful with sun protection after eating
What are the drugs that cause photosensitivity reactions?
Zhu Suyan introduced that common drugs are ciprofloxacin, norfloxacin, levofloxacin, doxycycline, voriconazole (long-term use), sulfonamides in antibacterial drugs; hydrochlorothiazide in diuretics and compound antihypertensive drugs containing hydrochlorothiazide; antiarrhythmic drugs amiodarone, tretinoin, isotretinoidine and some antineoplastic drugs. Some Chinese medicines also have photosensitivity reactions, such as Jing mustard, parsnip, Du huo, Bai Zhi, bone fat, rue and so on.
In addition to drugs, food can also cause photosensitivity reactions, such as lemons, lime, mangoes, amaranth, rape, purslane, celery, eggplant, fig tree sap, psoralen seeds, etc., these plants contain furan coumarin, furocoumarin itself is not active, but exposure to UVA radiation can induce luminescence sensitivity reactions.
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How to prevent drug-induced photosensitivity reactions? Zhu Suyan suggests:
Patients with a history of photosensitivity reactions should be cautious about using photosensitive drugs or foods;
Avoid the midday sun (10:00 to 16:00), when ultraviolet rays are strongest;
Medications taken once a day can be taken in the evening if they do not have to be taken in the morning to reduce possible photoallergic reactions;
During the use of photosensitive drugs and for 5 days after discontinuation, contact with sunlight or ultraviolet rays should be avoided;
When contact with light is unavoidable, protective measures should be taken when going out (long-sleeved shirts and trousers, wide-brimmed hats), and sunscreens with a broad spectrum effect on ultraviolet rays can be selected.
How to choose and use sunscreen?
1. Use a broad-spectrum sunscreen (protects both UVA and UFB) and take both SPF and PA into account when purchasing. SPF is an abbreviation for sun protection factor, and the coefficient after the spf value refers to a time range in which ultraviolet radiation on the skin does not cause harm. PA is an abbreviation for production grade of uva, and the "+" denotes the product's ability to defend against long-band UVA. pa++: effective; pa++: fairly efficient; pa+++: very efficient.
2. Sunscreen must be applied in sufficient amounts and repeatedly to all areas of skin exposed to the sun to provide effective protection.
3. Teaspoon rule: Refers to applying about 1 teaspoon of sunscreen to the face and neck, a total of 2 teaspoons on the front and back of the torso, 1 teaspoon each for the upper limbs, and 2 teaspoons each for the lower limbs. (1 teaspoon equals approximately 5ml)
4. Application timing: Apply sunscreen 15-30 minutes before sun exposure so that a protective film can be formed on the surface of the skin. It is recommended to wait at least a few minutes (preferably 10-20 minutes) after applying sunscreen before putting on clothes. Apply again every 2 hours in prolonged sun exposure.