Zel's Vegan NutGourmet

Zel Allen Goes Nuts for Good Health


Posted by Zel Allen's nutgourmet on January 22, 2012

Within a few hours after I posted my family’s experience with allergic rashes from consuming mangoes and cashews, I received the comment below. It’s so well explained in scientific terms I thought it important to share in a post rather than a comment.

The information comes from Sandra J. Baker, author of The Poison Oak & Poison Ivy Survival Guide.

Thank you so much Sandra. Your information explains the science behind my husband’s and two sons’ itchy rashes after eating mangoes and cashews. Hopefully, this post and the previous one will benefit others who suffer the misery of itchy skin rashes and haven’t discovered the cause.

Sandra writes:
I can add to your quest for information. Mango, cashew and poison oak, ivy and sumac are all in the family Anacardiaceae. Then poison oak, ivy and sumac join the genus Toxicodendron which contains the allergenic oil urushiol in its resin. But, mango and cashew also have allergenic oils. Mango has resorcinol, and cashew has anacardiol and cardol. All of these allergenic oils have enough similarity that if you are allergic to one, you are probably allergic to the others.

Mangos’ allergenic oil is mostly in the resin canals in the skin (always peel first before eating), and is thought to be somewhat weaker than poison oak/ivys’ oil. Some people are extremely allergic to it, but a mango grower said his workers usually don’t get much of a rash at the beginning of working with the plants. After a while, the sensitivity usually goes away. The oil can migrate from the skin into the flesh, so it is a good idea to stay away from all mango products, even juice if you know you are allergic.

All cashews imported into the US (even those labeled raw) are shelled and cooked a bit beforehand, because that will destroy the allergenic potential of the cashew nut shell oil that is between the honeycombed layers of the shell. (the oil of the cashew itself is harmless). (Poison oak/ivy and sumac oil is highly resistant to heat by the way.

Very seldom, cashews are accidentally imported without being cooked, and may have been contaminated from the shell cracking procedure, Rashes have been documented. This is a much smaller problem than that of mango rashes.



  1. Muriel Jelsma said

    Am a new vegan and just found this wonderful site.
    In the 70s I lived in Costa Rica and discovered I got a rash From raw green mangos. However, I amiable to eat them if cooked in chutney. However, raw ripe mangos don’t bother me so far.
    Growing up in the states, poison oak and poison ivy really attacked me—now I know why.

    • Zel Allen's nutgourmet said

      Hi Muriel, I’m so happy to know my blog post was helpful to you. Sometimes allergies pop up and surprise us. Even more surprising are the food families, such as mangoes, cashews, pistachios, poison oak, and poison ivy. Most people would never connect them. Since it’s been several months since my husband’s giant allergy rash disappeared, he’s feeling ready to give fresh mango a try, but in very limited quantity. Thanks so much for sharing. Zel

  2. Jayne said

    Thanks for all the interesting info. I myself broke out in a horrible rash. I went to the dr and have been tested for liver diseases, celiac ect. I just remembered tonite that I ate alot of honey roasted cashews. I am waiting for the results but I will call the dr to tell them my self diagnosis!

    • Zel Allen's nutgourmet said

      Hi Jayne,

      I’m always delighted when people are able to find that a-ha moment that brings awareness their weird rashes are the body’s way of telling them it wants to reject something you’ve eaten. Food allergies pose many challenges. The cashew/mango/poison ivy connection is one people rarely connect with, but if you read some of the other comments people have posted, you’ll find you’re not alone with this challenge. Both my husband and our son are now avoiding that food family and the ugly, itchy, and sometimes numbing rashes have disappeared. Your doctor may appreciate you calling this to his attention. Doctors don’t often connect health problems to foods that actually may be the culprit. So glad you’ve made that connection. Good health to you!


  3. Missy W said

    My friend told me about the connection between mangos and cashews because her son was just tested. I m wondering why I would have had an allergic reaction to a mango however I have absolutely no problems eating cashews. I am confused by this fact. Could there be something else in the mango that I am allergic to that isn’t in cashews?

    • Hi Missy,

      It could be the oils in the mango skin causing you an allergic reaction. That same composition of oils may not exist in cashews. However, I would suggest you not overdo the cashews–large quantities may just push your body’s tolerance over the edge and create an allergic reaction. My husband had been eating large quantities of cashews daily for years without a problem. About a year and a half ago we went to the Philippines and ate generous portions of mangoes daily. That triggered a dramatic reaction for my husband–an itchy rash on his legs and his back. Back at home, my husband dug into the cashews again, and shortly after, he began itching. Next day, his legs and back were broken out in a giant rash. And all it took was one handful of cashews. Just be cautious to learn your body’s level of tolerance, and then, don’t push it.

  4. Norma said

    The upset stomach I had eating cashews finally led to anaphylactic shook the last time I ate a small amount, so it is good to know the relationships. I think I will just avoid mangoes, as all our family are very allergic to poison ivy, etc.

    • Hi Norma,

      So sorry for this very tardy reply. I am sad to hear you had such a traumatic reaction to cashews. This cashew/mango/pistachio/poison oak/ and poison ivy family can be quite challenging and even life threatening for some. Since you had such a serious reaction, you probably ought to avoid all of the nuts and plants in this family. When eating at restaurants, be sure to ask about ingredients, especially in Asian or vegetarian/vegan restaurants where nuts are often part of the cuisine. With mangos, it’s often the skin that contains the problematic oils that cause allergic reactions for some people, but it’s best to be cautious and avoid them. Here’s to a healthy and safe life without the cashew/mango family!


  5. reizaal aziz said

    Hi, just to share some experience and insights on cashew and mango alergic reaction.

    I live in the tropic where we have a lot mango variety and probably a few cashew variety. The edible parts are eaten raw or cooked/pickled. The cashew shoots are often eaten as fresh salad.

    However particular care has to be taken while handling or harvesting the produce to avoid prolong contact with the sap. Cashew fruits used in cooking are usually boiled and strained, sometimes repeatedly. Although a really tree-ripe cashew fruit taste sweet, juicy and fragrant, it would leave your tounge and lips feeling unpleasant. Sap that stuck on your lips causes blisters. Cashew nut shells are throughly grilled over fire, preferably in a tin can filled with dry leaves and at times, loosely covered with a big lid cause the shells may explode and flew and hit you with the black booling sticky sap making a mark on your skin for days, or on your shirt forever. But I guess that’s what little kids do.

    There are a few exceptional variety of mango that cause blisters on the skin as well. The tree bark exudes lots of sap when broken, also from the thick skin of the fruit, but becomes less when ripen. The skin must be peeled generously thick to avoid that unplesant taste on your tounge. The fresh fruit is visually unappealing because of the dirty dried sap on the skin. These mango variety are never commercially exported. They are consumed locally as they have slightly different texture, taste and smell.


    • Hi Reizaal,

      Thank you so much for your informative comments about cashews and mangoes. I’m aware both cashews and mangoes grow in tropical climates where many varieties we never see commercially are available locally. Your comments inspired me to do some research on the processing of cashews, since they pose quite a challenge to safely separate them from their very hard shells in order to avoid burning the hands when they come in contact with the natural oils or sap. I hope to share some intriguing information about the cashew shell oil on this blog in the near future.

      I’m curious to know where you live.

      All the best,


  6. gary gough said


    I have been experiencing the mango reaction for a few years now, but I only get it on my lips. It feels sort of like really badly chapped lips with what feels like a bit of numbness and a bit of itching at different times. I don’t get the full body rashes right now, but I’m so afraid that it will grow into a life threatening issue that I just don’t eat Mango anymore, and its too bad because its literally my favorite fruit. Regarding Cashews, I hadn’t had any issue until very recently, now it appears that i get the same reaction on my lips as when i eat mango. Too bad, because wouldn’t you figure that Cashews are my favorite nut!

    • Hi Gary,

      I totally understand how frustrating it is to have to avoid mangoes and cashews, especially because mangoes are in season right now! What I’ve observed with both my husband and my son, who were experiencing similar symptoms from eating mangoes and cashews, is that by avoiding them completely for nearly a year, they were able to tolerate a small serving of mango occasionally–with several weeks between tastings. At other times, my husband would break out on his legs, chest, and back with an itchy rash that also made his skin feel hot. We, too, were concerned that it might become a life-threatening issue at some point, but our dermatologist said it was unlikely. He explained the skin reaction was pesty and uncomfortable, but not likely to send anyone to the hospital. Those with a severe nut allergy that sends them to the emergency room with anaphylaxis, must consider nuts and nut products to be life threatening throughout their lifetime. Because pistachios are in the same family as mangoes and cashews, I would avoid them, too. Take heart, though, there are many, many other delicious fruits and nuts to enjoy!

      Enjoy good health–eat lots of fruits and veggies,


  7. Dana said

    XUrushiol is found in Cahews, Pistachios and Mangoes as far as food items. But I am curious if anyone gets the same reactions with raw Carrots? I do and I am convinced the skin has urushiol but cannot findany literature to back this up.

    • Hi Dana,

      Apparently you have an allergic dermatitis when coming in contact with raw carrots. However, it’s not caused by urushiol, which is only found in cashews, pistachios, mangoes, poison oak, poison ivy, and sumac. There were a few studies done on people who worked in a factory where they were processing raw carrots and suffered from skin irritation. They problem disappeared when they stopped handling raw carrots for some time. It might help to wear gloves while peeling carrots, and then try cooking them. If you still have the irritation, carrots are not your best friend. Best to avoid them. The studies I looked at were brief, so I don’t know the culprit that causes the dermatitis. You’re fortunate that you can identify that raw carrots are responsible for causing the skin problems. Many people suffer for many months, or even years, without being able to find the cause.


      • Dana said

        Thank you. In my research, I have found that avocados and certain type of mushrooms also have urushiol.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: