use the same technique or procedure that you use for allergen testing. the negative control is the diluent used in the extract to be tested (e.g. 50% glycerin, sterile albumin saline with phenol, sterile buffered saline with phenol). with each skin testing method, in order for the reaction to positive skin test control-histamine (6 mg/ml histamine base) to be considered valid, erythema must be present which exceeds the respective negative control by 4 mm (∑e). a wheal reaction does not have to be elicited unless there is a wheal reaction to the respective negative control. in this case, the wheal of the positive control must exceed the negative control by 4 mm (∑w) in order to be considered appropriate. record measurement of erythema and wheal diameters. tables 1 and 2 summarize skin testing results with histamine base and controls in atopic and non-atopic subjects using four different devices and methods. (2) scratch, prick or puncture test: positive skin test control-histamine, 6.0 mg/ml histamine base. the scratch, prick or puncture test should be read in 15 minutes. if a large wheal reaction occurs before that time, wipe excess histamine solution from test site. a) use a sterile scarifier for each patient. hold the scarifier between the thumb and index finger, press the sharp edge of the instrument against the skin and twirl instrument rapidly. the scratch should disrupt the outer layers of epidermis down to the germinal layer, but should not produce immediate oozing of blood. the amount of pressure needed to produce a satisfactory scratch will vary between patients according to the thickness or fragility of their skin. apply one drop of positive skin test control-histamine to the scratch test site. b) prick or puncture test: prick tests are performed by placing a drop of extract on the skin and piercing through the drop into the skin with a slight lifting motion. puncture tests are performed by placing a drop of extract on the skin and piercing through the drop perpendicular to the skin with a device such as a prick lancetter. after about 1 minute the extract may be wiped away with a dry sponge.

e is 0.05 ml to 0.1 ml; for children 2 to 6 years, 0.15 ml; and children 6 to 12 years, 0.2 ml. single pediatric doses should not exceed 0.3 mg (ml). doses may be repeated as frequently as every 20 minutes, depending on the severity of the condition and the response of the patient. after administration of epinephrine, profound shock or vasomotor collapse should be treated with intravenous fluids, and possibly vasoactive drugs. oxygen should be given by mask. aminophylline or adrenal corticosteroids may be used if necessary after adequate epinephrine and circulatory support has been given. emergency resuscitation measures and personnel trained in their use should be available immediately in the event of a serious systemic or anaphylactic reaction not responsive to the above measures (ref. j. allergy and clinical immunology 77s (2): p. 271-273, 1986). 16 rarely are all of the above measures necessary, the tourniquet and epinephrine usually producing prompt responses. however, the physician should be prepared in advance for all contingencies. promptness in beginning emergency treatment measures is of utmost importance. adverse event reporting report all adverse events to jubilant hollisterstier llc customer technical services department at 1 (800) 992-1120. a voluntary adverse event reporting system for health professionals is available through the fda medwatch program. preprinted forms (fda form 3500) are available from the fda by calling 1 (800) fda-1088. completed forms should be mailed to medwatch, 5600 fisher lane, rockville, md 20852-9787 or fax to: 1 (800) fda-0178.

as there were no significant differences in their skin responses. summation of wheal (∑w) or summation of erythema (∑e) was determined by measuring the longest diameter and the mid-point orthoganol diameter of the wheal or erythema response and summing the two measurements. malling tested 25 subjects using a straight needle prick technique with histamine dihydrochloride 10mg/ml and found wheal single diameters of 5.4-8.5mm (mean 7 mm). 13 histamine dihydrochloride at 10mg/ml has been shown to elicit fewer false negative and false positive reactions than histamine dihydrochloride at 1mg/ml. 12 10mg/ml histamine dihydrochloride has been shown to be the appropriate strength to perform biological standardization using skin reactivity to histamine as a standard of comparison. 11,13 histamine table1 histamine table2