dermatitis
Introduction
Introduction Dermatitis and eczema are often used synonymously to refer to a type of skin inflammation that represents the skin's allergic response to chemicals, proteins, bacteria, and fungi. The term eczema has no special meaning, while dermatitis has a limiting meaning. If dermatitis is used instead of eczema as a diagnostic term, it refers to a combination of dermis and epidermis, which can be acute, subacute, and chronic. These three can exist together.
Cause
Cause
Bad living habits. Such as the use of hot water to wash your face, or excessive use of soap, facial cleanser and other skin cleansers, usually do not pay attention to the protection of ultraviolet light, etc., these physical and chemical stimulation will change or damage the skin's protective barrier and vascular regulation.
The causes of dermatitis are various and can be roughly divided into: mechanical, chemical, fungal, parasitic, allergic and other factors:
1. Mechanical, collar abrasion, autologous contusion, scratching cause traumatic dermatitis, burns, frostbite, radiation damage, etc.
2, chemical, chemical bathing agent irritating drugs, long-term stimulation of purulent secretions. Fungal, microspores, gypsum-like microspores, and hairy fungi.
3, parasitic, such as Demodex, sputum, sputum, sputum, sputum, schistosomiasis, hookworms and so on. In addition, food allergies, drug allergies can lead to dermatitis.
4. Bad living habits. Such as the use of hot water to wash your face, or excessive use of soap, facial cleanser and other skin cleansers, usually do not pay attention to the protection of ultraviolet light, etc., these physical and chemical stimulation will change or damage the skin's protective barrier and vascular regulation.
Examine
an examination
Related inspection
Skin test skin scratch test blood routine
1. Hematology and serological examination
Peripheral blood eosinophilia. T lymphocytes (especially Ts) are reduced. Serum IgE levels were significantly increased.
2. Skin test
Rapid allergic reactions to certain allergens (eg fungi, pollen, dander) are often positive. Intradermal test (delayed allergic reaction) with tuberculin, candida, etc., often negative or weakly positive.
3. Skin white scratch test
Use a blunt instrument to scratch the skin and white scratches on the skin (normal people are red).
Diagnosis
Differential diagnosis
Differential diagnosis of dermatitis:
1, chronic eczema: chronic eczema: often due to acute, subacute eczema repeated episodes of unhealed two into chronic eczema; can also start not obvious, because of frequent scratching, friction or other stimuli, so that the onset of the disease is chronic eczema. The performance is that the skin of the affected area is infiltrated and thick, the surface is rough, dark red or with pigmentation, and the lesions are mostly localized plaques, which are common in the hands, feet, calves, elbows, breasts, vulva, anus, etc., with clear edges. The course of the disease is chronic, can last for months or years, and can also be acute due to irritation.
2, scrapie: more common in the elderly, often related to the season, skin lesions are secondary.
3, lichen planus: occurs in the wrist flexion, forearm, calf extension, trunk, etc., rash is large, round or polygonal, flat papules, slightly rounded central, dark red, pale purple or normal skin color The surface has a waxy luster and histopathology has special changes.
4. Psoriasis: The base of the lesion is in reddish or dark red infiltrated. It is covered with silvery white scales. After peeling off the scales, the base has a thin film phenomenon and punctiform hemorrhage. Psoriasis damage is common in other parts of the body.
5, the primary skin amyloidosis: occurs in the calf stretch side, the skin lesions are high to the mung bean large round or semi-circular brown pimples, densely integrated with plaques without fusion, waxy luster, rough surface Inconsistent, the Congo red skin test was positive.
