Dinitrochlorobenzene patch test

Skin tests are the most commonly used in vivo test methods for measuring cellular immune function. Its essence belongs to delayed type hypersensitivity (type IV). When the body is infected by some bacteria (such as Mycobacterium tuberculosis, Brucella), viruses, or fungi, or contact with some small molecules, hapten substances, when combined with tissue proteins in the body to become a complete antigen. The body produces specific sensitized lymphocytes against these antigenic substances. When the corresponding antigen re-enters the body, the local lymphocytes release a variety of lymphokines. After 24 to 72 hours, the inflammation caused by mononuclear cell infiltration is manifested as redness and induration of the skin. This reaction is called delayed type metamorphosis. reaction. This reaction can be used as one of the indicators for judging the cellular immune function of the body. Basic Information Specialist classification: Oncology examination classification: immune examination Applicable gender: whether men and women apply fasting: not fasting Tips: Actively cooperate with the doctor during the examination. Normal value The degree of skin reaction was measured 48 to 72 hours after the challenge. Judging the results according to the following criteria: 0 no response. + Partially reddish or scattered in red small papules less than half of the area. ++ redness is more than half of the area of ​​the ring, which is a positive reaction. +++ Red pimples almost cover the surface of the ring skin. ++++ has blisters or ulcers. 90% to 100% of normal people are positive for 100μg DNCB. Clinical significance DNCB is a strong new antigen. The normal human DNCB skin test is almost positive, and it is not affected by the past exposure to DNCB as a population survey or patient test. The contact dose and reaction conditions are relatively consistent. But it must be sensitized beforehand, which is more troublesome. The positive test indicates that the cellular immune function of the body is normal, and it is generally used for the prognosis of surgical resection of malignant tumors. Those who had a positive skin test before surgery had a lower incidence of metastasis within 6 months after surgery than those who were negative before the skin test. Precautions (1) Pre-sensitization must be performed, and an attack test can be performed after 2 weeks. (2) DNCB can cause skin allergic contact, and later contact can lead to allergic dermatitis, and can also cause local redness of the skin. The rash often lasts for several weeks and pigmentation should be explained to the subject. Inspection process (1) Sensitization process: Disinfect the inner skin of the upper arm, and attach it to the skin of the upper arm with a plastic or stainless steel ring (with an inner diameter of 2 cm and an area of ​​about 3 cm 2 ). A suitable amount of sensitizing solution was extracted with a 1 ml syringe, and 0.1 ml (containing 1 to 2 mg of DNCB) was dropped on the surface of the skin in the ring, and the liquid was blown off with a rubber head to uniformly coat the surface of the skin in the ring. After the acetone is volatilized, the ring is removed and the surface is gently covered with a thin gauze. Remove the gauze after 24h. After 14 days, the sensitized site was observed to have spontaneous redness. If there was a reaction, it was also a positive reaction, and the challenge test could be carried out at a lower dose. (2) 14 days after the sensitization of the challenge process, 0.1 ml of a solution containing 50 μg or 100 μg of DNCB was applied to the inner skin of the forearm in accordance with the above-described sensitization procedure. Not suitable for the crowd There are no taboos. Adverse reactions and risks There are no related complications and hazards.

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