San Diego Anine-year-old boy is riding with his father south on I-5, headed for a fishing trip in Mexico. A bee flies into the cab of the truck and stings the boy. Within minutes, the boy is slumped on his dad's lap, unconscious, and turning bright red. At first the father considers pulling over and phoning for help. Thinking quickly, he turns off on I-8 and enters Mercy Hospital through the back entrance. The boy, now barely breathing, is taken into the ER. Moments away from death, the boy is revived by Dr. Davis Cracroft and the ER team.
Cracroft has worked in Mercy Hospital's emergency room for 25 years and has noticed a rise in the number of allergy patients. "There is a noted increase -- not just in my own experience, but with other ER doctors I've talked to throughout Southern California and even nationwide.
"If you take asthma as an example, in the United States and in other countries, there's a dramatic increase in asthma deaths. Not only is asthma increasing in its incidence, but it's also increasing in its complications and mortality rate. The statistics I'm familiar with show that in the 1980s there were roughly 1500 asthma deaths per year in the United States. It went up to about 3000, and it's continued to where it's three times the original number at about 5000 deaths per year."
Although no one seems to know the reason for the dramatic rise in allergy fatalities, Cracroft has his own suspicions. "There's a lot of reasons. One of them is that in San Diego's urban areas there is a higher incidence of allergic asthma that's directly related to poverty. Those people tend to use more over-the-counter medicines and have less access to medical care and end up using ERs as their primary source of care. So we see a lot more individuals who are poorly controlled showing up with their asthma in more advanced states. That's very, very common. There's also a higher incidence of asthma and smoke allergies in babies whose mothers smoke when they're in utero or they're exposed to smoke when they're newborns or young. There's also an increasing sensitivity to things like dust mites and cockroaches. They're allergic to those sorts of common inner-city bugs that are around. They're exposed early, they get repeated exposures during childhood, and they end up with asthma problems. Managed care and society has failed to care for a lot of these individuals appropriately, so they end up coming to the ER."
There are also allergy factors that may not necessarily be related to poverty. "We're seeing more exotic foods, different lotions, and people travel all over and get more exposure to these things. That can precipitate allergic reactions, but, fortunately, we're getting better at identifying them and desensitizing patients and treating them with better medicines."
Most people don't think of asthma as an allergy problem, but Cracroft explains that one of the two types of asthma is definitely an allergic reaction. "There's a type of asthma called 'intrinsic asthma' that's an inborn problem. Those individuals are generally not as sensitive to dust or weeds or pollens. Then there's 'extrinsic asthma,' which is triggered by what's around us in the environment. You'll see someone who might be allergic to milk or some sort of stimulant, and they'll come in after being exposed to it. Allergies are a kind of continuum: You can go from having just hives or a little rash, wheezing, and sneezing all the way to anaphylaxis, which is full-blown shock, requiring aggressive treatment to resuscitate the patient."
Sadly, Cracroft sees the "safer" environments for allergy patients disappearing. "The idea used to be that you would go to a climate like Arizona, where the air is clean. That was an ideal place for an asthmatic to go and get out of the inner city, but there's fewer and fewer of those places that don't have the air pollution and other problems."
The tricky (and dangerous) thing about allergies is that they are unpredictable. A person can be exposed to a substance repeatedly for years and, with no warning, have an allergic reaction. "On your next exposure, you can develop full-blown anaphylaxis. The boy who came in with the bee sting was in anaphylactic shock. We gave him epinephrine and got an IV going, ventilated and intubated him, and he began to respond over the next few minutes. As the epinephrine began to work, he blanched his skin in various areas, and they looked geographical -- it looked like a map of South America on his thigh and Antarctica on his chest -- and it all eventually coalesced into normal color. The redness went away, the swelling began to decrease, and he soon opened his eyes. They didn't know he was allergic to bee stings before that. If the father had stopped to call 911, the boy probably would have died."
Cracroft explains anaphylaxis, the worst of all allergic reactions. "There are a number of chemicals -- histamines and others -- that are released into the bloodstream when you have an advanced allergic reaction. They are all vasoactive substances that cause vasodilatation [dilation of the blood vessels], so you get this flushing. This can precipitate a dramatic drop in blood pressure -- which is what happened to this kid -- and the heart rate increases in response to this. Very often the release of these 'mediators' causes all of these problems and, if it persists, you can die a very painful death of hypoxemia -- your oxygen level goes down because you can't ventilate well."
Epinephrine, the drug used to treat anaphylaxis, is more commonly known as adrenaline. It dramatically reverses the dilation of blood vessels, causing vasoconstriction. By raising blood pressure, it brings the pool of blood back into circulation and forces the vessels to "clamp down" and do their job. Epinephrine is often carried in "kits" by allergy patients, so they can inject themselves when they feel anaphylaxis coming on.