Sometimes, the allergens are injected "intradermally" into the patients skin, with a needle and syringe. Common areas for testing include the inside forearm and the back. If the patient is allergic to the substance, then a visible inflammatory reaction will usually occur within 30 minutes. This response will range from slight reddening of the skin to a full-blown hive (called "wheal and flare") in more sensitive patients similar to a mosquito bite. Interpretation of the results of the skin prick test is normally done by allergists on a scale of severity, with +/− meaning borderline reactivity, and 4+ being a large reaction. Increasingly, allergists are measuring and recording the diameter of the wheal and flare reaction. Interpretation by well-trained allergists is often guided by relevant literature. Some patients may believe they have determined their own allergic sensitivity from observation, but a skin test has been shown to be much better than patient observation to detect allergy.If a serious life-threatening anaphylactic reaction has brought a patient in for evaluation, some allergists will prefer an initial blood test prior to performing the skin prick test. Skin tests may not be an option if the patient has widespread skin disease or has taken antihistamines in the last several days. Patch testing
Patch testing is a method used to determine if a specific substance causes allergic inflammation of the skin. It tests for delayed reactions. It is used to help ascertain the cause of skin contact allergy or contact dermatitis.
ANAVIP is the trade name of a snake antivenin indicated for the management of adult and pediatric patients with North American rattlesnake envenomation. As defined by the FDA, the proper name is crotalidae immune F(ab)2 (equine). It is manufactured by Instituto Bioclon for Rare Disease Therapeutics in the United States. ANAVIP is a divalent fragment antigen-binding protein, F(ab)2, derived from the blood of horses immunized with the venom of the snakes Bothrops asper and Crotalus durissus. The product is produced by pepsin digestion of horse blood plasma then purified resulting in a preparation containing >85% F(ab)2. == References ==