Ask the Pharmacist

Q) I think I got bit on my ankle since it is really itchy and red. Can you tell me what insect might be the culprit and what can I do about this itch?

A) As Canadians enjoy their newfound love for “staycations”, one of the few drawbacks can be a reintroduction to Ontario’s vast collection of insects and other biting species.

It is not uncommon at the pharmacy to be shown a few raised red and extremely itchy bumps on exposed areas of the skin from some hikers after they return from their adventure. It is human nature to want to know what exactly what “got you”, and in some cases this can be critical, but in general, regardless of the species that bit you, we treat the symptoms pretty much the same.

With respect to identifying bite marks, four factors must be assessed. These are:

  • the location of the bite(s) (i.e. arm or ankle)
  • whether they are grouped together, scattered or singular in nature
  • how quickly the symptoms first came
  • where you were when it happened (i.e. a hiking trail would yield a very different answer than if you were at the beach).

The vast majority of these cases can be treated without the need for medical attention but there are a few signs and symptoms that should trigger a visit to the emergency ward.

Essentially, there are two broad categories; Those associated with an anaphylactic type allergic reaction and those indicating an infection is setting in.

A severe allergic reaction can cause a multitude of symptoms affecting various parts of your body and can include hives, abdominal cramps, nausea and vomiting, swelling of the lips, tongue, face or throat, difficulty in breathing, a rapid heart rate and shock. This all tends to occur shortly after having been stung/ bitten and can be life-threatening if not treated promptly so someone experiencing this sort of cascade needs to be assessed at a hospital immediately.

In contrast, signs of an infection usually tend to be noticed a few days after the incident. People who have this sort of a reaction, even if it is fairly mild, should carry around an Epipen thereafter which can be a life-saver in allowing you time to get to a hospital after any subsequent bites. Even though a bite does not usually cause a large hole in the skin, it is more than large enough for bacteria residing on our skin to be able to penetrate in and begin the process.

Signs of an infection can be remembered by the acronym RASH. Thus we are looking for a spreading Reddish discolouration around the bite, increasing amounts of pain (or Ache) rather than a general easing of such, Swelling in the affected area and a feeling of increased warmth or Heat relative to the surrounding skin.

Most of these infections will probably require a prescription antibiotic to resolve so once again a doctor’s professional advice should be sought. However, these sorts of situations are the exceptions and not the rule.

Most people exhibit a typical reaction of pain and/or itching, redness and swelling at the site of the puncture as their body reacts to the venom or other noxious substance that has been deposited into the affected area by the insect’s mouth or stinger. Treatment of these milder reactions should begin with the removal of the stinger if it is still embedded within the skin. This is best done by gently scraping a flat-edged object such, as a health card, across the area. This will help curb the amount of toxin that is injected into your body subsequently minimizing your reaction and hastening your recovery. Do not use tweezers to accomplish this as it may cause more venom to be released when they squeeze together.

Next wash the affected area with soap and water to minimize the chances of an infection occurring down the road. Lastly, the application of a cold pack or ice (wrapped in a clean cloth to protect the skin from damage by the cold) on the area for 10 minutes at a time and repeated several times will help to reduce the swelling, pain and itchiness. If the itch persists, try using an over the counter cream such as 0.5 or 1% hydrocortisone or a more traditional remedy such as calamine lotion or one of the Aveeno anti-itch lotions and creams.

Ironic as it is, antihistamine creams such as Benadryl are generally not recommended as they are a fairly common source of allergic reactions. This however, has not stopped their use even though this has been well established for decades.

A remedy that your grandmother might suggest and often does wonders (as if there was ever any doubt! And yes, I suppose your grandfather is just as capable of coming up with this idea so please forgive my gender stereotyping) is the application of a thick baking soda paste over the area. These can be made by mixing a ¼ of a cup of baking soda with 1-2 teaspoons (5-10 ml’s) of water. It should be reapplied every 15 minutes or so. It is believed that the baking soda helps neutralize the acidity of the sting thereby helping to mitigate the inflammatory response.

It the itch is still an issue, an oral antihistamine such as cetirizine (Reactine) or desloratidine (Aerius) can be very helpful and can be safely taken by most anyone. The pill known as diphendydramine (Benadryl) is not used much anymore due to its inconvenience (it only lasts 4 to 6 hours whereas the above options are needed only once a day) and the significant amount of sedation it causes in most people who consume it (not surprisingly, it is also the active ingredient in most of the over the counter sleeping aids on the market). That being said, Benadryl is the drug of choice for an anaphylactic reaction due to its quick onset of action.

If pain is an issue, depending on other medical conditions you may have, acetaminophen (Tylenol) or one of the NSAID’s such as ibuprofen (Advil) or naproxen (Aleve) are usually more than up to the task.

As far as identifying a culprit, usually this is more for interests’ sake rather than of critical importance. The major exception to this is if it the bite is from a tick as these can lead to Lyme disease which is a nasty and progressive multi-system disease which can greatly hamper the quality of your life if not treated promptly. Most tick bites do not lead to this. In fact, the tick in question has to be an infected blacklegged tick and even then the risk of developing Lyme disease is somewhere between 1 and 3 %. However, just to be sure, it is suggested to remove the tick and store it in a bottle and contact the local public health office so it can be identified and tested if need be. Most tick bites will result in a benign itchy welt that disappears within a week.

A mosquito bite, which just about every resident of rural Ontario is all too familiar with, generally resembles a small, round puffy bump that appears soon after you’ve been bitten. Eventually the bump will become hard, red swollen and remain itchy. Often there are multiple bites in the same area and different areas.

A reaction to a fly bite often depends on the type of fly. It may cause sharp pain, with bleeding, itching and swelling. Sand fly bites in particular often lead to an itchy red welt. Black, deer and horse flies usually bite during the summer months and more typically at dawn or dusk and sand flies tend to do their feeding at night. Fire ant bites usually cause a burning sensation which becomes itchy and forms a raised red welt which lasts from 4 to 6 hours. Within about 24 hours, a pustule forms with blistering. These are usually found on the feet, ankles and lower legs. Bee and vespid (wasps, yellow jackets and hornets) stings typically present with an immediate pain sensation along with a wheal and flare reaction and localized swelling. With bees, there is typically only one sting (since the stinger is left behind in your skin) and the reaction lasts for 1-2 days. Vespids do not leave their stingers behind so you are more likely to have multiple stings and the reaction can last 2 to 7 days.

Regardless of the species, the usual course is sharp pain subsiding after a couple of hours with the majority of people exhibiting a red, swollen and irritated area of skin going out about 2 to 3 inches from the location of the bite/ sting. Swelling can last a week and redness should be pretty much gone after about three days. About 10% of the population will have a more exaggerated response where the redness and swelling will extend beyond 4 inches of the puncture site and the symptoms will actually continue to worsen over the first 48 hours before slowly resolving over a week to 10 days.

Of course, there are more critters than these that can “get” you and some people confuse bug bites with conditions such as scabies, shingles and cellulitis , all of which require  different interventions than the ones mentioned here. If you’re not sure what you are dealing with, feel free to drop by your local pharmacy for help in identifying just what you should do. For more information about this or any other health related issues, contact your pharmacist.