Solar dermatitis

Introduction to sun dermatitis Solar dermatitis (solardermatitis), also known as sunburn, is an acute phototoxic reaction caused by long-term exposure to ultraviolet light in the sun. It is clinically characterized by flushing, burning, and even blisters in the exposed area. It is mainly distributed in the exposed parts such as face, neck and back of the hand, especially for the forehead and cheeks. Often in the epidermis, erythema, papules, wheals or blisters, a small number of patients with erythema edema or plaque, a feeling similar to burns, after sun exposure symptoms are significantly worse, itching is unbearable, especially at night, after appropriate light There will be a turn for the better. Generally, the skin pigmentation of the affected area increases and it can continue to recur for many years. basic knowledge Sickness ratio: 0.05% Susceptible people: no special people Mode of infection: non-infectious Complications: nausea and vomiting

Causes of sun dermatitis

Environmental factors (35%):

Most of the sunlight is composed of visible light, and the spectral range is about 390-770 nm. In addition to its ability to stimulate the retina of the eye, it also has some biological activities. Infrared rays above 770 nm are invisible hot lines, which can make the skin redden. Ultraviolet light below 390 nm. The cause of this disease is 290 ~ 320nm medium wave ultraviolet. The cause of this disease is 290 ~ 320nm medium wave ultraviolet.

Body sensitivity (25%):

The degree of skin reaction varies depending on the time, range, environmental factors, and skin color. Heat can increase the body's sensitivity to ultraviolet light.

Body susceptibility (25%):

The onset of the disease is also related to the susceptibility of the individual. More common in spring and early summer. Plateau residents, snow exploration or water surface evils have more incidence.

Pathological change

The epidermis has individual necrotic keratinocytes to large confluent necrosis. The vasculature of the dermis is dilated, and a small amount of lymphocytes infiltrate around the blood vessels

Sun dermatitis prevention

Regularly participate in outdoor exercise to make the skin produce melanin to enhance the skin's sensitivity to sunlight, and try to avoid sun exposure. Protect yourself when going out, such as umbrellas, straw hats, gloves, etc. Some light-shielding agents can also be used externally: such as reflective sunscreen, 15% zinc oxide ointment; 5% titanium dioxide emulsion; 5% p-aminobenzoic acid emulsion or elixir; 10% salo ointment. It can be rubbed on the exposed skin 15 minutes before exposure.

Sunburn dermatitis complications Complications, nausea and vomiting

A small number of patients may also experience chronic damage during long-term exposure to the sun, such as thickening of the skin, keratosis, atrophy, telangiectasia, hyperpigmentation or loss.

Symptoms of sunburn inflammation Common symptoms Itching, drinking, nausea, dizziness, pain, palpitations, shock

When the skin is exposed to intense sunlight for several hours to ten hours, a rash occurs on the exposed parts such as the face, neck, back of the hand, and the like. According to the severity of skin reactions, it is divided into one-time sunburn and second-degree sunburn.

At one time, the sunburn showed diffuse erythema after partial sun exposure, and the boundary was clear, with a peak of 24 to 36 hours.

The second degree of sunburn is characterized by local skin redness and swelling, followed by blisters and even bullae, the blister wall is tense, and the blister fluid is pale yellow. Conscious symptoms have a burning or itching sensation. After the blister ruptured, it showed a smashed surface, and soon dried and crusted, leaving pigmentation or hypopigmentation.

The disease reaches its peak on the second day after sun exposure, which may be accompanied by systemic symptoms such as fever, headache, palpitations, fatigue, nausea, and vomiting. It can be recovered after one week.

Examination of sun dermatitis

Skin examination: Sunlight dermatitis often develops after exposure to the sun. Check the patient's face, neck, forearm extension, and the exposed parts of the back of the hand such as erythema, papules, wind lumps or blisters. Polymorphism means that the rash in different patients often varies, showing pleomorphism, but in a patient, the rash pattern is often single. Small papules and herpes are the most common, and a small number of patients present with erythema edema or plaque. The lesion is closely related to the daily exposure. After each irradiation, the lesion is obviously aggravated and the itching is intensified. The rash often recurs, and moss-like changes occur over a long period of time. The pigmentation increases and can last for many years.

Diagnosis and identification of sun dermatitis

diagnosis

1. There is a strong history of sun exposure.

2. The surface, neck, arms and chest V-shaped area and other exposed parts of the skin appear flushed, swollen, consciously burning or stinging, severe cases of blisters in the red swollen area, and even erosion.

TCM pathogenesis and syndrome differentiation: Chinese medicine believes that this disease is mostly endowed by endowment, the fur is not well-knit, and the complexion of wind and heat is harmful, so that heat can not be leaked and depressed.

TCM syndrome differentiation:

(1) Phototoxic invasion type:

The main card: diffuse flushing of the exposed skin, the surface is bright and radiant, consciously burning; can be accompanied by body heat, thirst, short red urine; red tongue, yellow fur, slippery pulse.

Dialectical: light poison attack, on the skin.

(2) Wet venom knot type:

Main card: The skin is red and swollen in the sun, there are blisters or bullae, the blister wall is tense, there is yellow exudation after breaking, consciously pain or itching; can be accompanied by body heat, thirsty does not want to drink more; tongue red, yellow coating Greasy, slippery.

Dialectical: wet poisonous knot, contained in the skin.

Differential diagnosis

1. Contact dermatitis: There is a history of contact irritant, and it has nothing to do with sun exposure. The skin lesions are consistent with the contact sites, the skin is red and swollen, and there are often bullae.

2. Niacin deficiency (pellagra): In addition to erythema at the exposed site, the boundary is clear, erythema with itching or burning pain, severe cases can occur bullae, and even ulcers, skin lesions are prominent, the nose is dark red, It is sputum-like, with powdery scales. The so-called niacin deficiency nose is quite special. In addition to skin lesions, there are digestive tract and mental symptoms.

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