Safe mushrooms can look like toxic ones

[00:00:00] Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Many toxic mushrooms closely resemble edible mushrooms. And for help understanding the differences, I am turning to Dr. Michael Hodgman. He's a medical toxicologist at Upstate working in emergency medicine the Upstate New York Poison Center. Welcome back to "The Informed Patient," Dr. Hodgman

[00:00:31] Michael Hodgman, MD: Thank you, amber. It's a pleasure to be here.

[00:00:35] Host Amber Smith: Now, people can buy several varieties of mushrooms at grocery stores. Can we assume that all of those are edible and safe?

[00:00:44] Michael Hodgman, MD: Yeah. The varieties that you'll find in a store are safe. Those are typically cultivated mushrooms, and basically you can be very comfortable that those are safe.

I would be more cautious of someone like if you go to a farm stand or a farmer's market that is selling mushrooms that have been foraged. I would be sure that, if someone's selling a mushroom there, ideally it's been something cultivated by someone who knows what they're doing. I would be very, very careful about buying a forged mushroom from somebody that you don't know, or don't trust.

But the store-bought ones: slam dunk. They're safe. One thing to remember with them, though, is like any other fruit you buy at a store, you want to wash them thoroughly before cooking them.

What percent of mushrooms are of a toxic variety?

That might depend on how you define toxic. I mean, there are many mushrooms that will give people gastrointestinal symptoms, perhaps some cramping, nausea, maybe some vomiting or diarrhea. And that's a pretty large group.

The ones that cause more serious toxicity, the ones that can lead to liver damage or liver failure, kidney injury, muscle injury, or the ones that have neurologic effects, those are ones that make up a very small percentage of the total number of mushrooms out there. I mean, there's thousands of species of mushrooms, and those ones that are the really, really dangerous ones, the ones that we worry most about at the poison center, they make up a minority of the mushrooms out there.

[00:02:26] Host Amber Smith: How many calls about mushrooms does the poison center get, typically?

[00:02:31] Michael Hodgman, MD: We get, over the course of a year, maybe about 150, 140 calls yearly. I just looked at this recently, and that's about the average over the last six years. And we're coming right into the season when we're going to start getting those calls because we get about 80% of our calls between June and October. So this is really, we're going into the peak mushroom season.

[00:02:59] Host Amber Smith: And are the calls about someone who's ingested mushrooms and now they're not feeling well, or are they asking you for help determining whether the mushroom is safe?

[00:03:10] Michael Hodgman, MD: We do not provide advice on whether a mushroom is safe or not. In fact, anybody who has a question like that, we would advise them to basically stay away from it. The majority of our calls are exploratory behavior by children five years or younger. And I'd say about half of our calls are basically in that five years and younger age group. And that's usually somebody out in the, a child out in the yard that takes a taste of a mushroom growing out in the yard. And those are usually what we call the little brown mushrooms. And those are the ones that if they're going to cause any symptoms at all, are usually ones that may cause a little bit of GI (gastrointestinal) upset.

[00:03:53] Host Amber Smith: So do you ask the callers to save any of the mushroom that wasn't eaten so that it can be identified later if the person gets really sick from it?

[00:04:04] Michael Hodgman, MD: Yes. Yes, we do. And there's some important things there, if we're saving a mushroom for further identification. What I should say is in most of these children, these younger children that get into it, those are for the most part we can poison information specialists in the poison center, we can manage those at home with a follow-up call, and make some decisions there.

When we need, when we have real concerns about the mushroom exposure, it's best to have an uncooked specimen, and with that uncooked specimen, storing it in a paper bag, not a plastic bag, because it'll decompose more rapidly if it's not allowed to breathe. And also, if you're sending a photograph of it, it's a good idea to put a coin or a ruler or something next to the mushroom so that we can get a sense of the size of it if we're even trying to make a preliminary assessment of what it might be, based on a photograph that might be sent to us.

But for storage, if we need to ship it somewhere to have a mycologist do a more definitive identification of it, it's best to store it in a paper, in a paper bag that's just loosely closed.

[00:05:19] Host Amber Smith: What is the most dangerous or the most feared mushroom in Central New York?

[00:05:24] Michael Hodgman, MD: In Upstate, in fact in New York and the Northeast, and probably everywhere in the United States, the most feared mushroom is from the genus, Amanita. And the Amanita mushrooms, many of them contain what are called Amanita toxins, and the Amanita toxins are the ones that can cause profound liver injury and, at times, even lead to liver failure. And it can be a very challenging thing to manage.

[00:05:55] Host Amber Smith: What does that mushroom look like?

[00:05:58] Michael Hodgman, MD: That is a mushroom -- again, I don't want to get into... Mushroom identification should be, people who do it regularly should really learn from somebody else who's experienced. But those are typically the ones we see in Upstate New York that are all white. They'll start coming out here in midsummer and all the way into fall. And they typically are all white. They may start with looking like just a small bulb coming out of the ground. And then as they grow up, the cap opens up, and those are the most dangerous ones in Upstate New York.

[00:06:33] Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with medical toxicologist Dr. Michael Hodgman about mushrooms. So when we say a mushroom is toxic, is it toxic to handle or touch, or only to ingest?

[00:06:51] Michael Hodgman, MD: For the most part, most mushrooms, the toxicity is from ingesting. There are some, such as puffballs -- if you may have seen those dried puffballs that when they pop and they release their spores in the air -- some people may have developed some respiratory symptoms associated with one of those. But basically when we're worried about mushroom toxicity, we're worried about ingestion.

[00:07:19] Host Amber Smith: So how soon after ingestion would a person maybe develop symptoms, and why is this important for you at the Poison Center to know about that?

[00:07:31] Michael Hodgman, MD: One of the most important things, pieces of information that we want to know at the poison center if somebody has an illness following a meal that had a mushroom in it is the time to the onset of the GI symptoms. Most of the mushrooms that are just, you might call the simple GI mushrooms that are going to give persons a GI illness, those tend to come on within the 90 minutes up to a couple hours after ingesting. So it's a relatively early onset of GI illness, and it typically isn't that severe, and it'll typically settle down within five or six hours or so.

In contrast to that, the Amanita- containing mushrooms that contain the Amanita toxin, their characteristic is the GI symptoms don't start until about five or six hours after the meal, after the ingestion. And so if somebody calls us and they have had this delayed onset of gastrointestinal symptoms, we get really, really worried that this might be an Amanita toxin.

Now the other time we'll get worried is, you know, people sometimes mix mushrooms. And so they may have mixed in one that gives you the early GI symptoms with one with an Amanita in it as well. So the person that develops the early GI symptoms, but they don't get better, six hours, seven hours, and they still have a lot of GI symptoms, we get worried there, too.

[00:09:02] Host Amber Smith: So are those people the ones that are told to go to the emergency department?

[00:09:07] Michael Hodgman, MD: Absolutely. Absolutely. If we have a suspicion of an Amanita toxin, we want to start treatment as soon as we can because unfortunately we don't have any magic bullet that prevents the liver injury that's already happened. We have medications that may ameliorate it, may reduce the amount of toxicity and may help the liver recover a bit. But again, the sooner we start treatment, the better.

[00:09:34] Host Amber Smith: Now, some people are interested in and involved in foraging mushrooms on their own from their yard or from the wild. Is that something that can be done safely?

[00:09:46] Michael Hodgman, MD: Well, in the right circumstances. What I would say is... the short answer would be, unless you have some experience with a more experienced forager, I would avoid it. But I think the best way to learn is not just, I mean, field guides are helpful. They can be really, really helpful. You know, there's online tutorials that you can look at, field guides. There's even some apps for phones now where you can take a picture of the mushroom, and it'll tell you what it is.

But I wouldn't rely on any of those. And in fact, one real question I would say is that, there was a study done last year with the phone apps, and the scary thing was, is they were no better than about 50 to 60% accurate at identifying these mushrooms that could be liver toxic. And so I wouldn't trust any of those. So as I said, those are all good, useful tools, but for somebody getting started, I think they're tools that you use with somebody that's an experienced forager or mycologist, because there are lookalikes out there, and the lookalikes can fool you.

You know, one unfortunate example we see in Upstate New York, or actually see everywhere in the U.S., is a recent immigrant from another country may see a mushroom here. It looks identical to one that was very edible in their home country. But it's not the same mushroom, not the same species here in the U.S. And we've had some unfortunate cases of liver injury from consuming an Aminita-containing mushroom in scenarios like that.

[00:11:27] Host Amber Smith: So toxic mushrooms don't have any features that you can look for that would distinguish them or that would tell a novice that they're toxic, it sounds like?

[00:11:39] Michael Hodgman, MD: Not really. I mean, again, there are morphologic features, and as I said, any white mushroom in New York, just stay away from. Chances are it's an Amanita-containing one. But there's other things you can look at. We can look at the pattern of the gills on the underside, if the gill's attached to the stalk or not? Is the mushroom hollow or solid if we crush it? Is there a color that the the skin takes on when it's crushed? Those are all tools in the field that people will use. And then there's other fancier things that can be done later on to investigate mushrooms. But I think those are the typical field ones that are used.

[00:12:20] Host Amber Smith: Now, what about, we've heard of hallucinogenic mushrooms. Are those considered toxic? And, do they grow in the wild, randomly?

[00:12:27] Michael Hodgman, MD: Well, probably the most common hallucinogenic mushroom is in the group, the Psilocybe group that contains psilocybin, which is an LSD-like compound that naturally occurs in these mushrooms. And they grow in the wild. In the United States, probably their most prominent area they grow is up in the Pacific Northwest. But these are a mushroom that have a predilection to growing in pastures with cow dung and things like that. And so, in the southeastern U.S., Psilocybe species are pretty common as well. I don't know if they grow in the wild in New York, but that's just really my lack of knowing that.

Psilocybin is becoming more and more in the press. I'm sure a lot of people listening to this have read about them. And, psilocybin, you can buy it online now, perhaps illicitly, here in New York State. But, -- and that's probably addressing your question -- what's being sold is probably, for the most, part cultivated psilocybin, but it does grow in the wild.

[00:13:33] Host Amber Smith: Now, you mentioned mushrooms needing to be washed before you eat them or prepare them. If you have a toxic mushroom and you wash it and you cook it, will that get rid of the toxins?

[00:13:48] Michael Hodgman, MD: No. That's an important point you bring up there, is, cooking a mushroom that contains the Amanita toxins, cooking does not inactivate the toxin.

I mean, there are mushrooms, even edible mushrooms, where you should cook them. Morels are a delicacy that grow in the late spring in much of the country, and even those should be cooked. You can get some GI illness if you don't. But for these, for some of the dangerous mushrooms that can cause liver injury or muscle injury or kidney injury, cooking does not inactivate the toxins. So never assume the cooking is going to make it safe.

[00:14:32] Host Amber Smith: Alright, well that's important information. I appreciate you making time for this interview, Dr. Hodgman.

[00:14:37] Michael Hodgman, MD: Oh, you're quite welcome. And thank you for having me.

[00:14:41] Host Amber Smith: My guest has been medical toxicologist, Dr. Michael Hodgman from Upstate's Department of Emergency Medicine and the Upstate New York Poison Center. "The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at upstate.edu/informed. If you enjoyed this episode, please tell a friend to listen too. And you can rate and review "The Informed Patient" podcast on Spotify, Apple podcasts, YouTube, or wherever you tune in. This is your host, Amber Smith, thanking you for listening.