Red Fire Ants Can Do More than Ruin a Picnic

I was recently stung by some red fire ants while working in the Seabrook garden so I did some more research on how to treat the stings.

Who are these fiends?

The red fire ant, Solenopsis invicta, (invincible stick) live in and around us everywhere and particularly are fond of golf courses and gardens that get plenty of sun.  These unwelcome residents came from South America and with the exception of humans have no natural enemies and this explains their ubiquitous presence now throughout most of the South and certainly in South Carolina.  A survey conducted in just South Carolina revealed that in the 1990, physicians reported treating 5000 cases of imported fire ant stings on humans. This represented a 14-fold morbidity. In all, there were 27 hospitalizations, one death and 170 cases requiring imported fire ant desensitization by an allergy specialist.  Undoubtedly with the growth in ant and human population since 1990 we are talking about a much higher incidence of stings.  In fact, in infested areas like Charleston County it is estimated that half of the population will be stung by a fire ant each year.
These terrors are different from the regular black ant that used to be a nuisance only because they spoiled picnics – these are slightly larger than black ants, a quarter of an inch long, reddish-brown to black and live in mounds with long, radiating underground tunnels.  However, if unsure whether you are dealing with fire ants or regular ants it won’t take long for them to let you know.  The disturbed and aggressive fire ants will swarm onto you and with a signal all the female ants will bite your skin and insert their stinger and quickly inject venom in that spot and rotate around and inject more venom nearby.  The immediate a correct response is to kill all you can find on you immediately.

Why is the sting worse than the bite?

The fire ant bites the flesh to grab hold, and this is done so quickly and sharply that there is little pain.  What inflicts the burn (hence the name fire ant) is the venom injected by a stinger.  The venom is water-insoluble and nonproteinaceous and contains hemolytic factors that cause the release of histamine and other vasoactive amines.  These produce itching and redness immediately and a bacterial uninfected pustule at the sting site after several hours.  The venom also contains several allergenic proteins that can cause anaphylaxis in patients who are allergic to the proteins.   Antigenic similarity exists between these proteins and bee and wasp venoms.

First aid for the stings includes:

1. Move rapidly away from the nest
2. Quickly remove or kill ants on skin and clothing – to prevent further stings
3. Wash the area gently with soap and water to rid the skin of any venom on it
4. Disinfect bite with alcohol
5. Place cool cloth or ice cloth on sites for 15 minutes
6. Try dabbing the site with one of the following: diluted (1:1) bleach solution, Kleen ‘Em Away Naturally, calamine Lotion, Enzyme cleaner or meat tenderizer
7. Consider a spraying topical (cortisone) or systemic (oral) antihistamine (e.g. benadryl) 
8. Do not scratch the pustule because this can lead to infection  

The natural course is for the site to burn for several hours, then over 24 hours a pustule develops with itching, and over several days if not scratched the lesion will slowly disappear.  Scratching can introduce infection and should be cleaned with alcohol.  Rarely (0.5%) of patients will have an allergic response immediately or over the first few hours.  The symptoms of this are difficulty breathing, light headedness and weakness.  If allergic reaction occurs immediate medical attention by call 911 is indicated.

Bottom Line

Be careful to avoid fire ants – when out scan the ground for mounds or other evidence of these vicious pests.  The sting is painful and the pustule persists for about a week.  These ants do more than ruin a picnic so be prepared for the inevitable bite and sting.