Bug Bites: Symptoms and When to See the Doctor
Guest: Dr. Bill Simpson – Department of Family Medicine, MUSC
Host: Dr. Linda Austin – Psychiatrist, MUSC
Dr. Linda Austin: I’m Dr. Linda Austin. I’m interviewing Dr. Bill Simpson, who is Professor of Family Medicine at the Medical University of South Carolina. Dr. Simpson, I know one of your areas of interest is a problem that, probably, every single human being has had at some time in their life, which is bug bites.
Dr. Bill Simpson: Especially in the Charleston area.
Dr. Linda Austin: Now, let’s take it from the point of view of someone who wakes up in the morning, let’s say, or late in the afternoon, looks at their skin, and they see a red bump. What is the first thing that person should look at to make a decision about whether it’s just something that’s going to go away, or whether they really ought to have a doctor take a look at it?
Dr. Bill Simpson: Well, it’s hard to say for sure. But I guess the main thing would be to look and see whether they have any other symptoms to go along with it; if there’s something new about the symptomatology: if the area is very itchy, if it’s irritated, if it looks like there’s pus in the area, or infection in the area. If so, they might want to do something more than to just observe and watch. The most important thing, obviously, is to know whether or not there’s a systemic reaction to the bite; if that’s what it was.
Dr. Linda Austin: Systemic, meaning?
Dr. Bill Simpson: Meaning somewhere other than where the bite is, you have symptoms. So, if you have a bite, or a spot, or red spot, on the back of your hand, and you have hives, or welts, on your back, that’s a systemic reaction to that bite; if it was a bite.
Of course, if you wake up with it, it’s hard to tell whether it even was a bite or not. You may have to sort of watch and see what develops. But if you have those distant symptoms from where the bite was, that may suggest a systemic reaction, an allergic reaction, to the bite.
Dr. Linda Austin: And then would that necessarily be a reason to call your doctor, or might you be able to treat that with Benadryl, or something like that?
Dr. Bill Simpson: If this goes away with treatment like Benadryl; like an over-the-counter antihistamine, to decrease the reaction, then that’s probably a reasonable thing to do. The problem, of course, is if you have had one of these, and you have systemic symptoms, then the next one may be more severe. So, if you know it was an insect bite, and you have these distant symptoms from where the bite occurred, then that would be trigger to go to see the doctor that time.
Dr. Linda Austin: The second time, is that right?
Dr. Bill Simpson: Right.
Dr. Linda Austin: I suppose it would never hurt to give your doctor a call if you were really unsure; and, probably, a lot of times, people are unsure.
Dr. Bill Simpson: Sure. It’s fine to get that reassurance by talking to the physician about what’s going on. It is a worry, though, that some people may miss that first one, and then have the second one that could potentially produce a severe reaction.
Dr. Linda Austin: Let’s talk about, then, just to kind of recap, what the warning signs are to you, as a doctor, that suggest to you that you really need to take this bug bite seriously.
Dr. Bill Simpson: Well, 85 percent of us have nothing but a local reaction to the bite; that would be a red spot where the bite occurred. About 15 percent have what’s called an exaggerated local reaction, which just means you have a bite on the back of your hand and the whole hand swells up; that’s 15 percent. Only one percent, or less, has a systemic reaction. You’ve been bit on the back of your hand and you have symptoms on your back, or a tightening in your chest, or a little bit of swelling around your tongue, or hives on your face. That’s the one percent that says this person has a systemic allergic reaction. They may need to have full intervention. They may need to go to the emergency room to get epinephrine for a systemic allergic reaction.
Dr. Linda Austin: Because that could, potentially, be life-threatening; that kind of very severe allergic reaction?
Dr. Bill Simpson: Right.
Dr. Linda Austin: So, when in doubt, if you have something like that, then call your doctor?
Dr. Bill Simpson: That one percent needs to see the physician. And, if they’ve been bit by a bee, a wasp, or hornet, a fire ant, we have hyposensitization serum to decrease the allergic response. If they’ve been bit by other insects, we don’t have hyposensitization serum for those as yet, so they have to be treated, preventively, by carrying an Epi-Pin, as should those people that have had a systemic reaction to the fire ant or the honey bee sting. They should also carry an Epi-Pin to prevent the allergic reaction, the systemic reaction.
Dr. Linda Austin: An Epi-Pin has epinephrine, or adrenaline, in it that will keep you from having that really severe allergic reaction?
Dr. Bill Simpson: Right.
Dr. Linda Austin: Let’s walk through the severe allergic, or anaphylactic, reaction. I think it’s something that people see in the movies sometimes; someone who can die of a bee sting, or something like that. Can you describe what it is that’s happening?
Dr. Bill Simpson: Well, the body is reacting to the foreign protein in the insect venom. That protein creates a response that pours out histamine. Histamine is the chemical that causes the welt, the hives, and the swelling in the throat, and the swelling in the lungs; the outpouring of fluid in response to that protein load that the person is susceptible to, or is allergic to. The pouring out of histamine produces a fall in blood pressure, decreased circulation to the heart, to the brain, an increase of fluid out of the lungs; the person has difficulty breathing, and sometimes constriction of the breathing tube, so that they can’t breathe normally, as with a severe asthma attack. And that can all happen within a matter of minutes, with that sudden allergic response to a foreign protein, essentially.
Dr. Linda Austin: And be life-threatening?
Dr. Bill Simpson: Right. We see one or two people a year who’re stung on the golf course, and die on the golf course, because they can’t get to treatment soon enough after a bee sting.
Dr. Linda Austin: So, are those, potentially, people who have been stung before but, maybe, didn’t take it too seriously, and didn’t know that they were susceptible to that kind of reaction?
Dr. Bill Simpson: Right. More than likely, a person who’s had at least this bite on the back of the hand and something else distant from the bite in their body’s response; like a hive, or a tightness in the chest, something that suggests a systemic response the second time they got stung, the next time they’re stung, they my have a full-blown anaphylaxis that could kill.
Dr. Linda Austin: And is that similar to the peanut allergies that one hears about? Is that the same process?
Dr. Bill Simpson: It’s very similar process, yes.
Dr. Linda Austin: Just a very severe allergic reaction. We tend to think of allergies as nuisances, but not necessarily life-threatening.
Dr. Bill Simpson: Right. And it’s only in a very small percentage of people that it is life-threatening. But the one percent or less that has that systemic response to a bite, or a sting; and usually it’s a sting, that’s the group that needs to see their physician very quickly. And that physician needs to refer them to an allergist to get the skin testing to see if they have something like a hyposensitization serum. If they don’t have that, they at least need to carry the Epi-Pin to prevent the anaphylaxis.
Dr. Linda Austin: I’m wondering if it would be wise, in one’s medicine cabinet, to always have at least some Benadryl, or some kind of antihistamine, on hand so that if you’re in the beginning stages of something, and you’re not sure, you can at least take that, and then carefully observe to see what happens.
Dr. Bill Simpson: That’s true. It’s a good thing to have the Benadryl around. It’s not enough, unfortunately, if it truly is an anaphylactic reaction. But it can delay, perhaps, by a few minutes. The allergists, now, even say that one Epi-Pin is not enough. You ought to have two, because sometimes one is not enough to get you to the emergency room if you have a systemic allergic reaction.
Dr. Linda Austin: Now, should anybody who has had even one episode, let’s say, of a bite plus hives, or a bite plus tightness of the chest, or swelling of the tongue, always have an Epi-Pin, or two, on hand?
Dr. Bill Simpson: Yes.
Dr. Linda Austin: Because they’ve that first, kind of, priming experience, which has put them at risk?
Dr. Bill Simpson: They’ve had the priming, and they’ve had the second one. Actually, the priming is when you almost have no response at all. The second one is probably the one when you got the bite on the back of your hand and the hive on your back. That one indicates a systemic response to the sting.
Dr. Linda Austin: And the third one could be life-threatening?
Dr. Bill Simpson: The third one could be. It’s not a guarantee by any means. It’s just that it’s possible.
Dr. Linda Austin: Do you ever outgrow that? I mean, if you, for example, have had that second reaction as hives in childhood, and now you’re 40 years old, are you still at risk?
Dr. Bill Simpson: You are still at risk. There is a possibility of becoming less sensitive; that’s true, but you are still at risk. If you’ve had an interim sting and had no reaction at all, that may suggest that you’ve lost that response. But it’s not a guarantee, so you really have to be vigilant the rest of your life.
Dr. Linda Austin: Dr. Simpson, thank you so much.
Dr. Bill Simpson: Thank you.
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