What Is Dermatitis?

Dermatitis is a general term for skin inflammatory diseases caused by various internal and external infections or non-infectious factors. It is not an independent disease. Its etiology and clinical manifestations are complex and diverse, and they occur repeatedly. Clinical treatment is difficult. The concept and classification of dermatitis and eczema is one of the issues that have been controversial in the field of dermatology. In the past, the two have been used as synonyms and are not strictly distinguished. Eczema, etc. At present, most people think that dermatitis refers to inflammation of the skin, such as contact sensitization and skin infections, while eczema refers to certain non-infectious inflammations, and those with relatively clear pathogenesis or clinical characteristics are called "some dermatitis" The general diagnosis of "eczema" was temporarily unclear. The International Classification of Diseases (ICD) -10 includes more than 20 diseases including contact dermatitis, atopic dermatitis, and neurodermatitis in the chapters on dermatitis and eczema. Clinically, a specific dermatitis is usually defined as a certain dermatitis according to the etiology, the location of the disease, or other clinical characteristics. For example, contact dermatitis caused by contact with a substance is called dermatitis caused by internal medicine. Eczema is a temporary concept. Once the cause is identified, this eczema should be diagnosed as dermatitis, and should not be diagnosed as eczema.

Basic Information

English name: dermatitis
Visiting department: dermatology

Multiple groups: People with sensitive skin and family history
Common causes: Related to factors such as infection focus, endocrine and metabolic changes
Common symptoms: Skin rashes, pimples, blisters, lichenification, etc.

Causes of dermatitis

The etiology of dermatitis and eczema is very complex and may be related to the following factors:

Internal factors

Chronic infections (such as chronic cholecystitis, tonsillitis, intestinal parasites, etc.), endocrine and metabolic changes (such as menstrual disorders, pregnancy, etc.), blood circulation disorders (such as calf varicose veins, etc.), neuropsychological factors, genetic factors, etc. .

2. External factors

It can be used by food (such as fish, shrimp, beef and mutton, etc.), inhalation (such as pollen, dust mites, etc.), living environment (such as cold, hot, dry, etc.), animal skin, and various physical and chemical substances (such as cosmetics, soap, synthetic fibers Etc.).

Dermatitis clinical manifestations

The clinical manifestations of dermatitis and eczema are diverse, and they can be divided into three types: skin lesions in the acute phase, subacute phase, and chronic phase.

Acute phase

Presented as erythema, edema, may be accompanied by pimples, papular rash, blister or erosion, exudation. The center of the lesion is often heavy and gradually spreads to the surroundings. The pathological manifestations are edema between epidermal cells, sponge formation, and intra-epidermal blisters.

2. Subacute phase

Blisters, swelling and exudation are reduced, scabs and scaling are present.

3. chronic phase

The skin is mainly rough and hypertrophic, with fresh moss-like changes, which may be accompanied by pigmentation or hypopigmentation, thickening of histopathological epidermis, hypertrophy of spinous layer, and infiltration of dermal papilla lymphocytes. Eczema in the hands and feet can be accompanied by nail changes. The rash is generally symmetrical and often recurrent. The conscious symptoms are itching and even itching.

The above three periods often have no obvious boundaries. Some patients can coexist, and some dermatitis do not necessarily go through three periods. The above clinical stages do not indicate the etiology or pathogenesis, but according to the etiology, location and clinical characteristics, dermatitis that can be classified for diagnosis can be referred to as classified dermatitis (eczema), such as stasis dermatitis and seborrheic dermatitis. The clinical features of dermatitis and eczema that cannot be further classified are called unclassified eczema (Table 1). Various different dermatitis and eczema have relatively specific clinical features.

Dermatitis check

It is mainly used for differential diagnosis and screening for possible causes. The results of different types of dermatitis tests are different. Some patients with routine blood tests have increased peripheral blood eosinophils, reduced T lymphocytes (especially Ts), and may have Serum eosinophilic cationic protein increased and serum IgE content increased. Immediate allergic reactions to certain allergens (such as fungi, pollen, and dander) are often positive. The patch test is helpful in the diagnosis of contact dermatitis. The fungal test can identify superficial mycosis, the tapeworm test can help eliminate scabies, and the serum immunoglobulin test can help identify congenital diseases with eczema and dermatitis skin lesions. Can help diagnose secondary bacterial infections, etc. Skin histopathology should be performed if necessary.

Dermatitis diagnosis

The diagnosis is mainly based on the comprehensive consideration of the etiology, the location of the disease, and the clinical characteristics. Common dermatitis that can be classified for diagnosis are contact dermatitis, atopic dermatitis, silting dermatitis, and seborrheic dermatitis. One or more skin inflammatory manifestations of primary or secondary skin lesions such as plaques, erosions, crusts, or lichenification; those who have the above clinical characteristics and cannot be further classified are collectively referred to as eczema, depending on the site Diagnosis such as perianal eczema, scrotal eczema, external ear eczema, breast eczema, eyelid eczema, etc., can also be diagnosed according to skin staging or season and other factors such as chronic eczema of the calf, summer dermatitis and so on. Eczema severity can be scored based on its area and the characteristics of the rash.

Differential diagnosis of dermatitis

Identification of the following diseases:

1. Differentiate from other types of dermatitis with specific etiology and clinical manifestations

Such as atopic dermatitis, contact dermatitis, seborrheic dermatitis, silting dermatitis, neurodermatitis and so on.

2. Differentiate from diseases with similar eczema

Such as superficial mycosis, scabies, pleomorphic solar rash, eosinophilia syndrome, Pelagic disease and cutaneous lymphoma.

3. Differentiation from rare congenital diseases with eczema-like skin lesions

Such as Wiskott-Aldrich syndrome, selective IgA deficiency, and high IgE recurrence infection syndrome.

Dermatitis treatment

First of all, pay attention to avoid the etiology or various suspicious pathogenic factors, avoid spicy food and alcohol consumption during the illness, and avoid excessive scalding and scratching. Infectious inflammation actively controls infection. The general treatment principles of non-infectious inflammation are as follows:

Systemic drug therapy

The purpose is to fight inflammation and relieve itching. Available antihistamines, sedative stabilizers, etc., generally should not use glucocorticoids.

(1) Acute phase and subacute phase: Calcium, vitamin C, etc. can be used for intravenous injection or procaine vein closure; For patients with skin lesions <30%, topical drugs can be combined with antihistamines and compound glycyrrhizin Oral administration; For patients with a skin area of 30%, 10% calcium gluconate or sodium thiosulfate or compound glycyrrhizin preparations can be administered intravenously; severe patients can be treated with hormones for a short period of time; and compound or alternate glycyrrhizin Or tripterygium or other immunosuppressants. After hormone withdrawal, continue to apply these drugs for about 2 weeks, and give antihistamines as appropriate. Or simply use Tripterygium wilfordii preparations, immunosuppressive agents such as cyclosporine until the disease is relieved; antibiotics should be appropriately given to patients with extensive skin lesions and erosions, exudates or secondary infections; use of immunosuppressive agents including azathioprine and cyclosporine as appropriate A (CYA) and interferon. Anti-relapse authors can try immunomodulators.

(2) Chronic period: Patients with skin lesions of <30% can take oral medication appropriately with antihistamines, compound glycyrrhizin, etc .; those with poor curative effects can add tripterygium preparation or immunosuppressant for short-term control. Discontinue medication after the illness; Most patients with skin lesions of 30% require oral compound glycyrrhizin, tripterygium preparations or immunosuppressants, immunomodulators, antihistamines; hormones are not recommended.

2. Topical medication

Follow the principles of topical use. Glucocorticoid cream can be used in the exudate during the acute phase. Cold and wet compress with 3% boric acid solution can be used for exudation. Glucocorticoid cream can be used after the exudation is reduced, or used alternately with oil; glucocorticoid can be used in the subacute phase. Hormone emulsions and pastes, antibiotics can be added to prevent secondary infections; ointments, plasters, and film coatings are used in the chronic period; sclerosing hormones can be injected intradermally with glucocorticoids.