Photosensitive dermatitis

Introduction to photosensitive dermatitis Photosensitive dermatitis is caused by the patient's allergy to ultraviolet rays. It is only found in a few people. The patient usually develops after 1 to 2 days after sun exposure. The rash occurs mostly in the face, neck and neck front "V" shaped area, the back of the hand and the upper limbs. It is characterized by small papules, small blisters, and conscious pruritus. If it is not actively treated, it can form chronic photosensitive skin diseases. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: dermatitis

Causes of photosensitive dermatitis

Adverse reactions with drugs

Antihypertensive drugs commonly used in clinical practice such as Zhenju antihypertensive tablets and compound antihypertensive tablets all contain thiazide diuretics. The literature reports that photosensitive dermatitis is more common. It is reported that taking Zhenju antihypertensive tablets causes photosensitive dermatitis. Adverse drug reactions.

Photosensitive dermatitis refers to skin reactions that occur after exposure to certain external photosensitivity and light. Common drugs that cause skin photosensitivity include: thiazide diuretics, chlorpromazine, non-steroidal anti-inflammatory drugs, tetracycline Sulfonamides, acridinium, amiodarone, quinine and quinidine, furosemide, etc.

Condition of occurrence

There are two conditions for its occurrence. One is that the exogenous photosensitizer is absorbed by the skin or absorbed by the internal environment. The other is that the skin absorbs certain energy and a certain wavelength of light, and the skin damage caused by it is various and can be expressed as edema. The distribution of erythema, papules, plaques, nodules, and skin lesions is limited to light-exposed parts, such as the head (hair thinning), the double forehead, the front of the ear, the back of the neck, the back of the hand, and other areas with clear boundaries. Epidermis erythema, occasional or maculopapular rash, reddish, bright red or dark red, light is scattered small pieces, heavy can be fused into large pieces, with or without edema, with disease can be accompanied by desquamation and pigmentation, all Patients have varying degrees of itching or burning sensation.

Photosensitive dermatitis caused by drugs is often misdiagnosed as general dermatitis or sunburn in clinical practice, which should be paid attention to. The diagnosis of this disease is mainly based on the fact that the damaged distribution site is in the light-exposed part rather than the general contact exposure site. The skin lesion is a manifestation of phototoxic reaction, and there is a clear history of taking light-sensitive drugs and the onset season is mostly in the early spring. According to this, it can distinguish between contact dermatitis, polymorphic sun rash and sunburn.

Photosensitive dermatitis is most often caused by the fragrance contained in cosmetics. For example, soap, facial cleanser, shower gel, etc. all contain a variety of complex perfume ingredients, which penetrate into the skin during bathing and cause allergic reactions to some people's skin under the action of scattering sunlight. As long as patients with photosensitive dermatitis insist on using cold water or warm water to bathe, do not use any cleansing skin care products on the skin, it can alleviate the condition of photosensitive dermatitis and prevent recurrence.

Photosensitive dermatitis prevention

Some people suffer from photosensitive dermatitis due to exposure to a large amount of ultraviolet radiation or eating some photosensitive vegetables. Doctors caution that photosensitive dermatitis should be prevented in summer.

Photosensitive dermatitis is most often caused by the fragrance contained in cosmetics. For example, soap, facial cleanser, shower gel, etc. all contain a variety of complex perfume ingredients, which penetrate into the skin during bathing and cause allergic reactions to some people's skin under the action of scattering sunlight. This type of patient can relieve the disease and prevent recurrence by sticking to cold water or warm water and not using any cleansing skin care products on the skin.

Photosensitive dermatitis complications Complications dermatitis

Photosensitive dermatitis usually occurs within one to two days after exposure to sunlight. The rash is more common in the face, neck, back of the hand and upper limbs. It is mainly characterized by small papules, small blisters, erythema, etc., consciously itching, some serious Non-illuminated parts can also cause rashes, no pain, abnormal itching, and disappear very slowly. If not actively treated, chronic photosensitive skin diseases can also be formed.

Photosensitive dermatitis symptoms Common symptoms Similar to urticaria skin...

Photosensitive dermatitis is sometimes considered to be an allergy to sunlight and is a response to the immune system caused by sunlight. Photosensitive dermatitis includes solar urticaria, chemophoto-sensitive dermatitis, and pleomorphic sun rash, characterized by a pruritic sudden rash that is exposed to sunlight. This light-sensitive body can be inherited. General diseases such as systemic lupus erythematosus and polyporphyria can also occur after exposure to sunlight.

classification

Solar urticaria is a wheal (large, itchy erythema) that occurs a few minutes after exposure to the sun. The wheal takes place within ten minutes of exposure to the sun and dissipates 1-2 hours after leaving the sun. People with large areas often have headaches, weakness, and nausea.

Chemical sun rash is characterized by progressive redness, inflammation, and sometimes bluish-purple spots after exposure to sunlight for a certain period of time. This reaction differs from the sun rash in that it is taken after the patient takes or excretes certain drugs. These drugs increase the sensitivity of some people's skin to ultraviolet light. Some people use it to cause itchiness caused by allergies caused by sunlight after taking certain drugs.

Polymorphic sun rash is a special response to sunlight that is unknown. It is a common skin disease that is easy for women and people who have no sun exposure. At the time of the attack, there were red pimples and irregular rashes in the sun. These rashes are usually itchy, usually 30 minutes to a few hours after sun exposure. Pimples and erythema usually resolve in a week or so. In particular, people with this situation continue to insist that outdoor sun exposure can reduce sensitivity to sunlight.

Photosensitive dermatitis examination

Phototoxic dermatitis is a localized flaky erythema with a burning sensation or pain. In severe cases, edema and blisters may occur or conjunctivitis and systemic symptoms such as headache, dizziness, fatigue, thirst, and nausea may occur. Can be diagnosed if:

1. There is a certain amount of occupational exposure history of photosensitive substances before the onset, and it is exposed to sunlight of a certain intensity and time.

2. Skin lesions occur in areas that come into contact with photosensitizing materials and are exposed to sunlight.

3, the same type of work, the majority of people under the same conditions.

4. Skin lesions originate within a few hours after exposure to sunlight.

5, after disengagement from the photosensitive substance or to avoid sunlight, the dermatitis subsides faster, and local pigmentation can be left in different degrees.

6, if necessary, can do a spot patch test, a sunburn-like reaction.

Diagnostic identification of photosensitive dermatitis

It can be diagnosed according to clinical manifestations and laboratory tests.

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