ADVERSE REACTIONS

Systemic reactions may range from mild exaggeration of the patient’s allergic symptoms to anaphylactic reactions. Very sensitive patients may show a rapid response. In some instances a severe systemic reaction with blood pressure fall and/or shock may occur. Quantitation of patient's sensitivity combined with careful early observation is essential for safe skin testing and treatment.

Other reactions include, but are not necessarily limited to urticaria, itching, edema of the extremities, respiratory wheezing or asthma, dyspnea, cyanosis, tachycardia, lacrimation, marked perspiration, flushing of the face, neck or upper chest, mild persistent clearing of the throat, hacking cough, or persistent sneezing.

1) Local Reactions

Small amounts of erythema and swelling at the site of injection are common, the extent varying with the patient. Such reactions should not be considered significant unless they persist for at least 24 hours or exceed 50 mm. in diameter.

Larger local reactions are not only uncomfortable, but also indicate the possibility of a systemic reaction if dosage is increased. In such cases the dosage should be reduced to the last level not causing the reaction and maintained at this level for two or three treatments before cautiously increasing again.

Large, persistent local reactions or minor exacerbations of the patient’s allergic symptoms may be treated by local cold applications and/or the use of oral antihistamines, but they should be considered a warning of possible severe systemic reactions and the need for temporarily reduced dosages.

A mild burning immediately after the injection is to be expected; this usually leaves in 10 to 20 seconds. Prolonged pain, or pain radiating up the arm, is usually the result of intramuscular injection, making this injection route undesirable. Subcutaneous injection is the recommended route.

2) Systemic Reactions

With careful attention to dosage and administration, such reactions occur infrequentIy, but it must be remembered that allergenic extracts are highly potent to sensitive individuals and OVERDOSE could result in anaphylactic symptoms. Therefore, it is imperative that physicians administering allergenic extracts understand and be prepared for the treatment of severe reactions.

Adverse reaction frequency data for allergenic extract administration is not available. Inherent difficulties in establishing such data are the wide variations in clinical allergy types, patient sensitivity, treatment schedules used by allergists, potency of extracts from various sources, etc.

It cannot be overemphasized that, under certain unpredictable combinations of circumstances, anaphylactic shock is always a possibility. Other possible systemic reaction symptoms are, in varying degrees of severity, fainting, pallor, bradycardia, hypotension, angioedema, cough, wheezing, conjunctivitis, rhinitis, and urticaria.17,18