Basis for diagnosis of drug allergic dermatitis

Pre-illness** history of medication; There is a certain incubation period; Sudden onset, symmetrical rash, widespread (except for fixed drug eruptions), bright color, etc.; self-perceived itching; Severe disease with mucosa, visceral organs and systemic acute symptoms.

Scarlet fever-like or morbilliform erythema and erythema multiforme are common types of drug-induced dermatitis. Drugs that are prone to cause this type of drug eruption include sulfonamides, barbiturates, salicylic acids, tetracyclines, antispasmodics, streptomycin, aldipine, griseofulvin, etc. These types of drug-induced dermatitis have a rapid onset, and the rash often occurs symmetrically on the trunk, limbs, and head and face, and in severe cases, it can affect the whole body, and the mucous membranes are involved, and can be accompanied by fever, headache, general weakness and other symptoms, or fever and systemic symptoms are not obvious.

Scarlet fever is a small erythema that appears on the base of **flushing, and there is no normal rash**. Although erythema is similar to the measles-like erythema, the rash is normal between the eruptions**. Erythema multiforme is large, edematous, and erythema iris may be seen as it expands periphally.

Judging from the rash alone, drug-induced dermatitis is more bright red than scarlet fever, measles, or erythema multiforme.

There is a history of obvious drug use for this disease, but not every patient can ask clearly, no history of contact with measles or scarlet fever, no acute tonsillitis, no perioral pale ring, strawberry tongue, linear rash, low or slightly increased white blood cells, and eosinophil leukocyte elevation is more obvious. Although the above information is helpful, the child sometimes has "upper sensation" or "tonsillitis", takes antibiotics and salicylic acid drugs, and then develops a rash, when the child has both upper respiratory catarrhal symptoms or symptoms of acute tonsillitis, and has a significant history of drug use, and the difference between scarlet fever or morbilliform eruption, drug eruption and scarlet fever, drug eruption and measles, and erythema multiforme and erythema multiforme does require considerable consideration. More importantly, once misdiagnosed, drug eruptions based on corticosteroid hormones will have serious adverse effects on scarlet fever or measles, and on the contrary, it is not right to use the drug eruption of scarlet fever or measles.

Therefore, careful diagnosis is required**. The Affiliated Hospital of Heilongjiang Youth Medical Association.

Answer]: The penicillin skin test is a type of intradermal test. Contact dermatitis is a type of hypersensitivity ridge that is commonly tested for allergens by patch testing. Radioallergen aspiration and dismantling assay (RAST) is commonly used to detect specific IgE.

Answer]: B Eosinophilia Clinical significance: (1) Allergic diseases:

Bronchial asthma, urticaria, drug-induced rash, angioedema, food allergies, tropical eosinophilia, serum sickness, hypersensitivity pneumonitis, etc. (2) Symptoms and parasitic diseases: psoriasis, eczema, pemphigus, dermatitis herpetiformis, fungal disease, lung fluke, hookworm disease, hycoccosis, schistosomiasis, filariasis, tapeworm disease, etc.

3) Hematologic diseases: chronic myeloid leukemia, eosinophilic leukemia, etc. (4) Drugs:

Antibiotics such as cefradine, cephalexin, cefuroxime, and cefoperazone are used. (5) Malignant tumors: some epithelial tumors such as lung cancer.

6) Infectious disease: scarlet fever. (7) Others:

Rheumatic diseases, adrenal insufficiency, etc.

Common manifestations of allergic reactions to the drug are dusty and do not include the nudance (a).Fixed drug eruption.

b.Multi-type red pai spots.

c.Sudden, generalized erythema.

d.Epidermolysis bullosa.

Correct answer: d

How to tell the difference between "allergies" and "dermatitis"?

Generally speaking, dermatitis is a disease caused by bacterial infection, the most common symptom is local redness, swelling and itching, while allergies are not, although allergies will also cause itchy feelings, but the main reason for allergies is that the patient is exposed to a certain self-allergic substance, which leads to the symptoms of erythema and itching. In addition,Relatively speaking, allergies are more serious than dermatitis, and severe allergies can be life-threatening, but dermatitis is not.

In fact, dermatitis is a kind of inflammation, there are many types, and different types of dermatitis have different symptoms, mostly because they have received internal or external infections, and even non-infectious factors may lead to the occurrence of **, therefore, if you find that there are erythema and red spots in the locality, accompanied by pain and itching, it is generally considered to be the cause of dermatitis, and it is recommended that the patient go to the **department of the hospital for examination** in time.

The allergic reaction refers to the body's immune response to some foreign substances that the human body is exposed to, and the immune response is disordered, which will lead to a large area of redness, red spots, itching and other symptoms on the patient's body, of course, because allergic reactions include many types, and their symptoms have individual differences, so the diagnosis of allergic reactions must be carried out in the hospital, it should be noted that if the allergic reaction is serious, it will be life-threatening, so once the abnormality is found, immediately go to the hospital for treatment.

Therefore, dermatitis is a disease caused by bacterial infection, which is generally not life-threatening, and will be cured after experiencing it, while allergies are caused by the disorder of the body's immune response, and in severe cases, it will even be life-threatening, and there is no way to stay away from allergens. Therefore, whether it is allergies or dermatitis, it is recommended to go to the hospital in time to avoid serious consequences.