Summertime Hazards

Just in time for summer, I thought I'd offer some pointers on parasites.

Of course, parasites exist year round. But as the weather gets warmer and our patients head outside to play in the dirt or splash around in the toddler pool, the possibility that they'll pick up one of the following five organisms increases.

Here they are in approximate order of the frequency that we see them in central Kentucky:

▸ Pinworms. By far the most common parasite seen in preschool children, the diagnosis is usually made by a parent who finds a little wriggling rice-sized creature in the child's diaper, underwear, or bedding. Treatment—liquid mebendazole or chewable pyrantel pamoate—is given once, then repeated about 10–14 days later.

Families should be advised to wash all bed linens in hot water to get rid of any residual eggs and to prevent reinfestation.

If the problem recurs, retreat the child and consider treating the whole family and the child's playmates. If the parent reports a third sighting after two rounds of treatment, I will ask that they actually bring the worm in.

Some parents become so excessively concerned that they misinterpret many things as pinworms. It's been quite interesting—I've seen husks of corn, pea shells, and little bits of mucus that aren't even organisms.

Once, we got back a housefly larvae from a child's stool. I'm not sure how it got there.

We've also seen the proglottid of a tapeworm—these often fold up on themselves, and can almost look like a pinworm. That child had been treated several times for pinworms before referral.

Another pinworm-related problem is that the child may continue to experience perianal or vulvar itching and continue to scratch even after the pinworms are eradicated. Sitz baths may be helpful in easing the irritation. If itching continues, applying 1% hydrocortisone cream to the area for no more than 1 week can often break the itch-scratch cycle.

Pinworms are often an emotional issue for families. It's important to convince parents that it's not because they or their child is dirty, but, rather, that they picked up pinworms from their friends. To diffuse the worry, I often tell parents that the upside of pinworms is that their child likely has good social skills.

▸ Giardia. Toddler pools are a frequent yet underrecognized source of giardia, which are more familiarly associated with food-borne outbreaks or with transmission via fresh water, such as mountain springs.

But “kiddy pools” in the backyard or even at professionally maintained pool complexes are a particularly likely source of giardia transmission. Because they're shallow, sunlight can degrade the chlorine to below the giardia-inhibiting levels, which are higher than needed for coliforms.

If you see more than one giardia patient from the same swim club or backyard pool, advise the swim club pool staff or pool owners to make sure the chlorine level is being monitored more often. We had a giardia outbreak in an upscale country club's pool, and the parents were mortified. Acquisition of giardia in the pool is likely due to other toddlers using the pool in diapers.

Giardia typically presents with diarrhea, cramps, an extreme amount of flatulence, and stools with a characteristic green bubbly appearance. Once you've seen a giardia stool, you will know it again. The diagnosis is made with a routine laboratory ova and parasite screen.

Furazolidone is the treatment of choice, but metronidazole also works. Of course, these are two of the worst-tasting medicines around. You might advise parents to try chasing it with a spoonful of Hershey's syrup. In older kids, a Hershey's Kiss works. No, I receive no funding from Hershey's.

▸ Ascaris. In a typical scenario with ascaris, the parent reports finding a 2- to 4-inch long “fishing worm” in the child's diaper. This is the easy diagnosis.

However, we had a case last year of a 4-year-old who had been diagnosed with asthma and who continued wheezing over an 8-month period despite all the usual asthma medications including a couple rounds of steroids. He had eosinophilia, which had been attributed to allergies.

As it turned out, this child did not have asthma at all, but rather a classic case of Loeffler's pneumonia, in which the ascaris larvae had migrated to his lungs, triggering eosinophilia and an asthma-like picture. We treated the child with mebendazole twice a day for 3 days, and both the wheezing and the eosinophilia disappeared. The child didn't wheeze thereafter.

Ascaris was far more common in years past. These days we've become such a clean society we just don't see it as much as we used to and it's dropped off the radar screen. Yet, in addition to the pulmonary case, we've actually had two more classical ascaris cases just in the last month—one was spotted by the mother in the child's diaper, the other in the toilet.

Ascaris can produce abdominal pain and discomfort, and may lead to malabsorption syndrome, weight loss, or vitamin deficiency. Very large infestations can sometimes lead to intestinal obstruction—I saw a case of this a few years ago, when I was working in Omaha, Neb. The parasite also can migrate to the bile duct and obstruct the liver.

With lower-level infestations, however, the nonspecific epigastric and diffuse abdominal discomfort may be indistinguishable from functional abdominal pain.

However, if the problem persists—or if the child has wheezing or pneumonia symptoms, get a complete blood count. If you see eosinophilia, order an ova and parasite stool exam.

▸ Dientamoeba fragilis. If you trained prior to the 1990s, you probably were taught that D. fragilis is merely a harmless commensal and doesn't need to be treated. However, it has become apparent in the last decade or so that this parasite can cause symptoms, including chronic loose stools, cramps, and flatulence. The child usually doesn't look especially ill but complains of abdominal upset and may have up to three to four loose, mucus-containing stools per day.

And D. fragilis hangs on—after the second week or so, you can be fairly certain it's not rotavirus or another acute gastrointestinal virus. Along with giardia, also think of D. fragilis.

Interestingly, D. fragilis will often piggyback with pinworms, literally sticking itself to the pinworm eggs. Therefore, if you've already treated the child for pinworms and the GI symptoms continue, you might want to order another ova and parasite stool exam. This time, however, special procedures are required. Because this organism is so fragile—hence the name—it deteriorates rapidly at room temperature. Parents should be instructed to collect a fresh stool sample and immediately place it in a preservative-containing pack (we use ParaPak). For the greatest sensitivity, three samples must be collected on separate days. Sensitivity of the test is about 85%–90% for three samples taken on consecutive days, and up to 95% if collected on alternate days.

The order to the lab should request a microscopic exam, not just an antigen screen. Microscopy will pick up not only D. fragilis, but other less common parasitic creatures that you don't want to miss, such as Entamoeba histolytica. Parents must also be told to stop any over-the-counter antidiarrheals such as Kaopectate or Pepto-Bismol 24–48 hours prior to the first stool collection, as these agents will make it difficult to visualize the parasites.

If D. fragilis is identified, treatment is metronidazole three times a day for 10 days. Because of fecal-oral transmission, consider asking the parents if they're experiencing loose stools as well. Symptoms tend not to be as dramatic in adults as in kids, but if they've got D. fragilis and you treat them, they often feel better.

▸ Blastocystis hominis. Although similar to D. fragilis in structure, B. hominis is still considered a commensal and not pathogenic. However, if present in high enough quantities, it can still cause nonspecific abdominal symptoms, loose stools, flatulence, and mucus in the stool. If you do a work-up and find no other explanation for the symptoms, it's not unreasonable to treat using the 10-day metronidazole regimen. Here, too, a microscopic exam is necessary to visualize the cysts in the stool.

Although not known to produce any toxins or direct irritants to the colon, it's possible that B. hominis just has not been investigated closely enough to prove its pathogenicity. New data suggest this may be the case.

We've been seeing more lab reports of both D. fragilis and B. hominis in the last few years. It's not clear whether that's because of increased use of preservative packs or actual increased prevalence.

But we definitely seem to get more calls from parents and physicians about parasites as the weather gets warmer.

Just in time for summer, I thought I'd offer some pointers on parasites.

Of course, parasites exist year round. But as the weather gets warmer and our patients head outside to play in the dirt or splash around in the toddler pool, the possibility that they'll pick up one of the following five organisms increases.

Here they are in approximate order of the frequency that we see them in central Kentucky:

▸ Pinworms. By far the most common parasite seen in preschool children, the diagnosis is usually made by a parent who finds a little wriggling rice-sized creature in the child's diaper, underwear, or bedding. Treatment—liquid mebendazole or chewable pyrantel pamoate—is given once, then repeated about 10–14 days later.

Families should be advised to wash all bed linens in hot water to get rid of any residual eggs and to prevent reinfestation.

If the problem recurs, retreat the child and consider treating the whole family and the child's playmates. If the parent reports a third sighting after two rounds of treatment, I will ask that they actually bring the worm in.

Some parents become so excessively concerned that they misinterpret many things as pinworms. It's been quite interesting—I've seen husks of corn, pea shells, and little bits of mucus that aren't even organisms.

Once, we got back a housefly larvae from a child's stool. I'm not sure how it got there.

We've also seen the proglottid of a tapeworm—these often fold up on themselves, and can almost look like a pinworm. That child had been treated several times for pinworms before referral.

Another pinworm-related problem is that the child may continue to experience perianal or vulvar itching and continue to scratch even after the pinworms are eradicated. Sitz baths may be helpful in easing the irritation. If itching continues, applying 1% hydrocortisone cream to the area for no more than 1 week can often break the itch-scratch cycle.

Pinworms are often an emotional issue for families. It's important to convince parents that it's not because they or their child is dirty, but, rather, that they picked up pinworms from their friends. To diffuse the worry, I often tell parents that the upside of pinworms is that their child likely has good social skills.

▸ Giardia. Toddler pools are a frequent yet underrecognized source of giardia, which are more familiarly associated with food-borne outbreaks or with transmission via fresh water, such as mountain springs.

But “kiddy pools” in the backyard or even at professionally maintained pool complexes are a particularly likely source of giardia transmission. Because they're shallow, sunlight can degrade the chlorine to below the giardia-inhibiting levels, which are higher than needed for coliforms.

If you see more than one giardia patient from the same swim club or backyard pool, advise the swim club pool staff or pool owners to make sure the chlorine level is being monitored more often. We had a giardia outbreak in an upscale country club's pool, and the parents were mortified. Acquisition of giardia in the pool is likely due to other toddlers using the pool in diapers.

Giardia typically presents with diarrhea, cramps, an extreme amount of flatulence, and stools with a characteristic green bubbly appearance. Once you've seen a giardia stool, you will know it again. The diagnosis is made with a routine laboratory ova and parasite screen.

Furazolidone is the treatment of choice, but metronidazole also works. Of course, these are two of the worst-tasting medicines around. You might advise parents to try chasing it with a spoonful of Hershey's syrup. In older kids, a Hershey's Kiss works. No, I receive no funding from Hershey's.

▸ Ascaris. In a typical scenario with ascaris, the parent reports finding a 2- to 4-inch long “fishing worm” in the child's diaper. This is the easy diagnosis.

However, we had a case last year of a 4-year-old who had been diagnosed with asthma and who continued wheezing over an 8-month period despite all the usual asthma medications including a couple rounds of steroids. He had eosinophilia, which had been attributed to allergies.

As it turned out, this child did not have asthma at all, but rather a classic case of Loeffler's pneumonia, in which the ascaris larvae had migrated to his lungs, triggering eosinophilia and an asthma-like picture. We treated the child with mebendazole twice a day for 3 days, and both the wheezing and the eosinophilia disappeared. The child didn't wheeze thereafter.

Ascaris was far more common in years past. These days we've become such a clean society we just don't see it as much as we used to and it's dropped off the radar screen. Yet, in addition to the pulmonary case, we've actually had two more classical ascaris cases just in the last month—one was spotted by the mother in the child's diaper, the other in the toilet.

Ascaris can produce abdominal pain and discomfort, and may lead to malabsorption syndrome, weight loss, or vitamin deficiency. Very large infestations can sometimes lead to intestinal obstruction—I saw a case of this a few years ago, when I was working in Omaha, Neb. The parasite also can migrate to the bile duct and obstruct the liver.

With lower-level infestations, however, the nonspecific epigastric and diffuse abdominal discomfort may be indistinguishable from functional abdominal pain.

However, if the problem persists—or if the child has wheezing or pneumonia symptoms, get a complete blood count. If you see eosinophilia, order an ova and parasite stool exam.

▸ Dientamoeba fragilis. If you trained prior to the 1990s, you probably were taught that D. fragilis is merely a harmless commensal and doesn't need to be treated. However, it has become apparent in the last decade or so that this parasite can cause symptoms, including chronic loose stools, cramps, and flatulence. The child usually doesn't look especially ill but complains of abdominal upset and may have up to three to four loose, mucus-containing stools per day.

And D. fragilis hangs on—after the second week or so, you can be fairly certain it's not rotavirus or another acute gastrointestinal virus. Along with giardia, also think of D. fragilis.

Interestingly, D. fragilis will often piggyback with pinworms, literally sticking itself to the pinworm eggs. Therefore, if you've already treated the child for pinworms and the GI symptoms continue, you might want to order another ova and parasite stool exam. This time, however, special procedures are required. Because this organism is so fragile—hence the name—it deteriorates rapidly at room temperature. Parents should be instructed to collect a fresh stool sample and immediately place it in a preservative-containing pack (we use ParaPak). For the greatest sensitivity, three samples must be collected on separate days. Sensitivity of the test is about 85%–90% for three samples taken on consecutive days, and up to 95% if collected on alternate days.

The order to the lab should request a microscopic exam, not just an antigen screen. Microscopy will pick up not only D. fragilis, but other less common parasitic creatures that you don't want to miss, such as Entamoeba histolytica. Parents must also be told to stop any over-the-counter antidiarrheals such as Kaopectate or Pepto-Bismol 24–48 hours prior to the first stool collection, as these agents will make it difficult to visualize the parasites.

If D. fragilis is identified, treatment is metronidazole three times a day for 10 days. Because of fecal-oral transmission, consider asking the parents if they're experiencing loose stools as well. Symptoms tend not to be as dramatic in adults as in kids, but if they've got D. fragilis and you treat them, they often feel better.

▸ Blastocystis hominis. Although similar to D. fragilis in structure, B. hominis is still considered a commensal and not pathogenic. However, if present in high enough quantities, it can still cause nonspecific abdominal symptoms, loose stools, flatulence, and mucus in the stool. If you do a work-up and find no other explanation for the symptoms, it's not unreasonable to treat using the 10-day metronidazole regimen. Here, too, a microscopic exam is necessary to visualize the cysts in the stool.

Although not known to produce any toxins or direct irritants to the colon, it's possible that B. hominis just has not been investigated closely enough to prove its pathogenicity. New data suggest this may be the case.

We've been seeing more lab reports of both D. fragilis and B. hominis in the last few years. It's not clear whether that's because of increased use of preservative packs or actual increased prevalence.

But we definitely seem to get more calls from parents and physicians about parasites as the weather gets warmer.

Just in time for summer, I thought I'd offer some pointers on parasites.

Of course, parasites exist year round. But as the weather gets warmer and our patients head outside to play in the dirt or splash around in the toddler pool, the possibility that they'll pick up one of the following five organisms increases.

Here they are in approximate order of the frequency that we see them in central Kentucky:

▸ Pinworms. By far the most common parasite seen in preschool children, the diagnosis is usually made by a parent who finds a little wriggling rice-sized creature in the child's diaper, underwear, or bedding. Treatment—liquid mebendazole or chewable pyrantel pamoate—is given once, then repeated about 10–14 days later.

Families should be advised to wash all bed linens in hot water to get rid of any residual eggs and to prevent reinfestation.

If the problem recurs, retreat the child and consider treating the whole family and the child's playmates. If the parent reports a third sighting after two rounds of treatment, I will ask that they actually bring the worm in.

Some parents become so excessively concerned that they misinterpret many things as pinworms. It's been quite interesting—I've seen husks of corn, pea shells, and little bits of mucus that aren't even organisms.

Once, we got back a housefly larvae from a child's stool. I'm not sure how it got there.

We've also seen the proglottid of a tapeworm—these often fold up on themselves, and can almost look like a pinworm. That child had been treated several times for pinworms before referral.

Another pinworm-related problem is that the child may continue to experience perianal or vulvar itching and continue to scratch even after the pinworms are eradicated. Sitz baths may be helpful in easing the irritation. If itching continues, applying 1% hydrocortisone cream to the area for no more than 1 week can often break the itch-scratch cycle.

Pinworms are often an emotional issue for families. It's important to convince parents that it's not because they or their child is dirty, but, rather, that they picked up pinworms from their friends. To diffuse the worry, I often tell parents that the upside of pinworms is that their child likely has good social skills.

▸ Giardia. Toddler pools are a frequent yet underrecognized source of giardia, which are more familiarly associated with food-borne outbreaks or with transmission via fresh water, such as mountain springs.

But “kiddy pools” in the backyard or even at professionally maintained pool complexes are a particularly likely source of giardia transmission. Because they're shallow, sunlight can degrade the chlorine to below the giardia-inhibiting levels, which are higher than needed for coliforms.

If you see more than one giardia patient from the same swim club or backyard pool, advise the swim club pool staff or pool owners to make sure the chlorine level is being monitored more often. We had a giardia outbreak in an upscale country club's pool, and the parents were mortified. Acquisition of giardia in the pool is likely due to other toddlers using the pool in diapers.

Giardia typically presents with diarrhea, cramps, an extreme amount of flatulence, and stools with a characteristic green bubbly appearance. Once you've seen a giardia stool, you will know it again. The diagnosis is made with a routine laboratory ova and parasite screen.

Furazolidone is the treatment of choice, but metronidazole also works. Of course, these are two of the worst-tasting medicines around. You might advise parents to try chasing it with a spoonful of Hershey's syrup. In older kids, a Hershey's Kiss works. No, I receive no funding from Hershey's.

▸ Ascaris. In a typical scenario with ascaris, the parent reports finding a 2- to 4-inch long “fishing worm” in the child's diaper. This is the easy diagnosis.

However, we had a case last year of a 4-year-old who had been diagnosed with asthma and who continued wheezing over an 8-month period despite all the usual asthma medications including a couple rounds of steroids. He had eosinophilia, which had been attributed to allergies.

As it turned out, this child did not have asthma at all, but rather a classic case of Loeffler's pneumonia, in which the ascaris larvae had migrated to his lungs, triggering eosinophilia and an asthma-like picture. We treated the child with mebendazole twice a day for 3 days, and both the wheezing and the eosinophilia disappeared. The child didn't wheeze thereafter.

Ascaris was far more common in years past. These days we've become such a clean society we just don't see it as much as we used to and it's dropped off the radar screen. Yet, in addition to the pulmonary case, we've actually had two more classical ascaris cases just in the last month—one was spotted by the mother in the child's diaper, the other in the toilet.

Ascaris can produce abdominal pain and discomfort, and may lead to malabsorption syndrome, weight loss, or vitamin deficiency. Very large infestations can sometimes lead to intestinal obstruction—I saw a case of this a few years ago, when I was working in Omaha, Neb. The parasite also can migrate to the bile duct and obstruct the liver.

With lower-level infestations, however, the nonspecific epigastric and diffuse abdominal discomfort may be indistinguishable from functional abdominal pain.

However, if the problem persists—or if the child has wheezing or pneumonia symptoms, get a complete blood count. If you see eosinophilia, order an ova and parasite stool exam.

▸ Dientamoeba fragilis. If you trained prior to the 1990s, you probably were taught that D. fragilis is merely a harmless commensal and doesn't need to be treated. However, it has become apparent in the last decade or so that this parasite can cause symptoms, including chronic loose stools, cramps, and flatulence. The child usually doesn't look especially ill but complains of abdominal upset and may have up to three to four loose, mucus-containing stools per day.

And D. fragilis hangs on—after the second week or so, you can be fairly certain it's not rotavirus or another acute gastrointestinal virus. Along with giardia, also think of D. fragilis.

Interestingly, D. fragilis will often piggyback with pinworms, literally sticking itself to the pinworm eggs. Therefore, if you've already treated the child for pinworms and the GI symptoms continue, you might want to order another ova and parasite stool exam. This time, however, special procedures are required. Because this organism is so fragile—hence the name—it deteriorates rapidly at room temperature. Parents should be instructed to collect a fresh stool sample and immediately place it in a preservative-containing pack (we use ParaPak). For the greatest sensitivity, three samples must be collected on separate days. Sensitivity of the test is about 85%–90% for three samples taken on consecutive days, and up to 95% if collected on alternate days.

The order to the lab should request a microscopic exam, not just an antigen screen. Microscopy will pick up not only D. fragilis, but other less common parasitic creatures that you don't want to miss, such as Entamoeba histolytica. Parents must also be told to stop any over-the-counter antidiarrheals such as Kaopectate or Pepto-Bismol 24–48 hours prior to the first stool collection, as these agents will make it difficult to visualize the parasites.

If D. fragilis is identified, treatment is metronidazole three times a day for 10 days. Because of fecal-oral transmission, consider asking the parents if they're experiencing loose stools as well. Symptoms tend not to be as dramatic in adults as in kids, but if they've got D. fragilis and you treat them, they often feel better.

▸ Blastocystis hominis. Although similar to D. fragilis in structure, B. hominis is still considered a commensal and not pathogenic. However, if present in high enough quantities, it can still cause nonspecific abdominal symptoms, loose stools, flatulence, and mucus in the stool. If you do a work-up and find no other explanation for the symptoms, it's not unreasonable to treat using the 10-day metronidazole regimen. Here, too, a microscopic exam is necessary to visualize the cysts in the stool.

Although not known to produce any toxins or direct irritants to the colon, it's possible that B. hominis just has not been investigated closely enough to prove its pathogenicity. New data suggest this may be the case.

We've been seeing more lab reports of both D. fragilis and B. hominis in the last few years. It's not clear whether that's because of increased use of preservative packs or actual increased prevalence.

But we definitely seem to get more calls from parents and physicians about parasites as the weather gets warmer.