A variety of insect may bite humans, but the bitting insects that are likely to produce serious reactions are generally of the order hymenoptera and include bees, wasps, yellow jacket, ants and hornets. The venom of such insects contain, in addition to sensitizing agent, varying amount of several vasoactive substances such as histamine, serotonin and kinins.
The most clinical features following insect bites vary a great deal from person to person depending upon the age and state of sensitization from previous stings. Fortunately most of the patients have only the lesser degree of reactions comprising pain, smarting and oedemia at the site of the bite with or without some reactionary fever. However, in a small group of cases generalized reactions of an allergetic nature may occurs ranging from mild cough and wheezing to urticaria, laryngeal stridor, dysphagia and mental confusion. In the worst cases, anaphylactic reaction in the form of hypertension, shock and collapse may develop unexpectedly and with marked rapidity after the sting.
Some insects leave parts of their stinging apparatus in the skin of the victim. This sting should be carefully scraped out with a finger nail or wiped out with a piece of cloth, but squeezing should not be done as this may result in the injecting more venom. Thereafter, hydrocortisone ointment may be applied as promptly as possible, coupled with any measures to deal with secondary infection. If the sting is on an extremity, a tourniquet should be applied proximally to decrease absorption of venom.