Polymorphous Solar Rash Disease Overview
Polymorphous Solar Rash (PolymorphousLightEruption) is a recurrent, chronic, multiple photosensitive skin disorder.
Polymorphous sun rash etiology
Entropology
The cause of the disease is not well understood, but genetics and geography may be important causative factors. Most believe it is a delayed-onset allergic reaction caused by sunlight sensitization. The disease is immunosensitizing to skin antigens that are altered by ultraviolet radiation. The causative spectrum is predominantly medium-wave ultraviolet. The process of sun exposure and the amount of exposure to which it is subjected varies greatly from patient to patient. Some patients have a family history of photosensitization.
Pathological changes
Papillary edema of the dermis, pale and purplish, the superficial dermis and deep blood vessels around the display of dense lymphocytic infiltration, some can be seen in the epidermal changes of spongy edema, intraepidermal blisters and individual necrotic corneal prion cells, and some only the superficial dermis or the deep layers of the dermis perivascular fire, and no obvious papillary edema.
Polymorphic sun rash clinical manifestations
This disease is prevalent in adults, mostly in the late spring and early summer seasons, fall and winter natural healing. The skin lesions occur in sun-exposed areas, with the face and neck more common. The rash is polymorphic and lasts for about 3 to 5 months. According to the morphology of the rash is divided into four types.
1. The plaque-type rash is a red or dark red flaky or slightly elevated infiltrative plaque, about 20 to 25 mm in size, severe and long-lasting, there may be surrounding capillary dilatation and skin xeroderma changes. Hyperpigmentation remains after the rash subsides. Self-awareness of severe itching. This type is common.
2. The erythema multiforme type rash is a red or dark red edematous papule of varying sizes with clear borders and slightly elevated edges.
3. Eczema type skin redness, swelling, the surface can be seen dense pinhead to rice size papules, blisters, vesicles, crusts and flaking, like eczema-like appearance, sometimes moss-like changes, self-conscious itch. This type is rare.
4. Itchy rash type rash is erythema, rice to mung bean size papules, nodules. The longer the course of the disease can be mossy. After subsiding, there is hyperpigmentation. Self-existent itching. This type is rare.
Diagnostic differentiation of polymorphic sun rash
Based on the history of onset, season of prevalence, chronic process, ultraviolet erythema reaction test shows an abnormal reaction, etc., it is not difficult to diagnose. This disease needs to be differentiated from the following diseases:
1. Eczema lesions occur independently of irradiation and season.
2. Erythema multiforme damage is often seen on the hands and feet, such as the typical iris-like erythema is easier to distinguish, the onset of the disease has nothing to do with light.
3. The lupus erythematosus rash is persistent erythema with keratinized phosphorescence, enlarged follicular openings, and atrophic scars and dilated capillaries.
4. Neurodermatitis papules are flattened in line with the dermatoglyphic line, independent of light exposure, and have no seasonal effect.
Polymorphic sun rash treatment
1. Local treatment before going out can be applied 15% zinc oxide ointment, 5% titanium dioxide cream, 4% benzophenone lotion or cream, dihydroxyacetone and naphthoquinone lotion, corticosteroid hormone cream, such as applying, 2 to 3 times a day.
2. Systemic treatment
(1)Antihistamine Cyproheptadine 2～4mg; Paracetamol 4～8mg once a day orally. Xis 10mg; Keminen 10mg once a day orally.
(2) Antimalarials chloroquine 250mg 2 to 3 times a day orally, after control of the disease is reduced to 1 to 2 weeks a day, after an interval of 2 to 4 days to pass off the amount of drugs once. Hydroxychloroquine sulfate 100mg once a day orally, pay attention to its side effects during the service, the latter is lighter than the former side effects.
(3)Corticosteroid hormone is used for severe rash, especially eczema-like hydrocarbon rash. Available prednisone daily 30 ~ 40mg oral, a week later, after the control of the disease gradually reduce the amount to stop.
(4) Azathioprine is effective in patients with severe photosensitivity and eczema-like changes. Successful treatment of severe polymorphic sun rash with azathioprine has been reported, but the authors believe that the drug is not suitable for most patients, and that azathioprine is a short-term interstitial therapy only for patients of non-reproductive age, with severe polymorphic sun rash, and who have not responded to other treatments. A dose of 50 mg twice daily usually results in relief in 2 to 4 months. In a few cases, the drug can be discontinued with 6 to 8 months. The white blood cells, platelets and liver function should be rechecked regularly during the medication.
3. Photochemotherapy 8-methoxypsoralen and long-wave ultraviolet (PUVA) irradiation is effective for active lesions. Oral 8-methoxypsoralen 20mg two hours before irradiation, PUVA irradiation should start from the smallest amount of phototoxicity or 1 joule. If irradiation in late spring and early summer before the season also has a preventive effect.
4. Traditional Chinese Medicine (TCM) treatment of rheumatism is based on dispersing wind and clearing heat, and the formula can be used to add or subtract Jing Fang Tang. Blood-heat type is to cool the blood and clear the heat, the formula with the wind soup. Eczema changes available gentian diarrhea liver soup plus reduction. The itchy rash change may use the dan jia jia xuan shan combined with the peach red four things soup to customize.
Polymorphic sun rash prognosis prevention
To avoid light as the principle, but also should often participate in outdoor activities, in order to receive a small dose of short time of ultraviolet radiation, gradually increase the amount of light, improve the body's ability to tolerate light exposure. To avoid sun exposure between 10 a.m. and 3 p.m.. If you have to work outdoors, you should wear protective clothing, straw hats and gloves.