Caterpillar Sting: Symptoms, Diagnosis, And Treatment

Did you spot rashes or red spots following a trip from the garden and think those might be caterpillar stings?

Contrary to what you might have come to believe, caterpillars are not entirely harmless. Some of them can give a really tough time and therefore, you should always proceed with caution.

Caterpillar stings are more common among children. They're curious about nearly everything. So they don't mind touching and handling the tiny and seemingly harmless caterpillars.

But, some species of caterpillars can sting and cause skin problems. As a responsible parent or guardian, you must know how to handle such situations. You should know how to diagnose and treat caterpillar stings.

Children and adults can face similar problems as well, and the severity can exceed beyond rashes to respiratory problems. So it's important to learn about the symptoms, diagnosis, and treatment of caterpillar rashes. All of that is covered in this article.

If you liked reading about caterpillars, you can also take a look at articles on the caterpillar cocoon and bird beak here at Kidadl.

What are itchy caterpillars?

A caterpillar is the larva of either a butterfly or moth. As you may know, larvae are immature and one of the earliest stages of an insect's lifecycle. While they may seem harmless, some caterpillar stings do hurt.

When the egg-laying season arrives, female moths and butterflies lay a lot of eggs on the leaves of trees or plants. A few of them survive and hatch into larvae. These larvae are voracious feeders and spend the majority of their time eating leaves.

As the larva grows, it develops and sheds the outer skin and then grows wings and hairs. Some caterpillars, like hickory horned devils, develop horn-like projections. It's these hairs that cause itchiness when you come in contact with a caterpillar body.

The next stage of a larva is the pupa. After the caterpillar has eaten enough and undergone several stages of molting, it prepares to pupate. After spending a few weeks as a pupa, it then transitions into a butterfly or moth.

Not all caterpillars are created equal. There are 180,000 various species. Some species can be called 'stinging caterpillars' because they sting and cause skin problems. Others only cause very mild reactions in comparison. Here are some species to be aware of:

Also known as the 'asp' or puss caterpillar, the flannel moth caterpillar is perhaps the most dangerous of all. That's because this small caterpillar is equipped with venomous spines. These spines are hidden underneath the fine silky hair that looks attractive at first.

When you come in contact with the spines, they cause a stinging rash that can be quite painful. They're found in certain southern states including Texas. Fortunately, they only live on oak trees and rarely come close to humans.

The Io moth is another stinging caterpillar that is covered with venomous spines over a green body. The tips are black in color but hard to notice.

Since they blend well with the summer foliage plants, you may not even realize and accidentally brush against their spiny bodies. The sting of an Io moth is usually quite painful. The Io moth is found primarily in the midwestern and eastern states of the US.

A spiny oak is full of spines. It has many extended lobes that contain venomous stinging hairs. They come in a variety of bright colors, which indicate that they're poisonous and potentially dangerous. The consequences of brushing against their spines go beyond rashes and may require taking painkillers. Spiny oak caterpillars are not particularly common.

The saddleback moth is characterized by a green patch on its back with a purplish-brown spot that seemingly looks like it wearing a saddle. Curious kids usually go ahead and rub the back to see if it's really wearing anything.

The four large projections of the saddleback, two at the front, two at the back, are spines containing poison. It can cause irritation that lasts for several hours.

The buck moth caterpillar not only looks dangerous but is dangerous. Their tufts are covered with spines that are connected to poison glands underneath their body.

Stinging strikes lead to painful rashes that can last for a day or two. They usually hide and live on oak trees and are seen during the spring season. These stinging caterpillars are common in midwestern and southern American states.

There are other stinging caterpillars like spitfire caterpillars. They have hairs throughout their body that go upright when touched. A spitfire caterpillar sting can be agonizing. They're endemic to Australia.

Most stinging caterpillars belong to the flannel moth family and go on to become moths. Then there are other species like the monarch butterfly and spicebush swallowtail that aren't dangerous to touch. These caterpillars go on to become butterflies. So it's safe to say only caterpillars of the moth family are dangerous.

Symptoms Of A Caterpillar Sting

When you come in contact with a stinging caterpillar, you may not even realize it at first. Then slowly the symptoms will start to emerge. Knowing about these will help confirm that you were stung by a caterpillar. Also, you will be able to gauge the severity of the situation and request adequate medical help.

The first symptom is an irritating rash with a burning sensation. It's called caterpillar dermatitis.

Depending on which stinging caterpillar you've come across, you will start to feel the irritation within 5-30 minutes. If you are stung by a flannel moth, you'll feel the pain almost immediately. Over time, it gets intense and the pain will stay for about 1-2 days.

If you are stung on the arm, the pain may extend to the armpit or axillary region. Stings of other caterpillars like the white flannel moth are relatively less severe.

The main culprit here is the tiny hairs or setae that some caterpillars have. These hairs carry poison compounds and release them when they perceive a threat.

Then, the reason why we feel pain is because of how our body reacts to the poison. When the caterpillar toxin from the hairs is released, it triggers an immune response. Our immune system, perceiving the toxic compounds as a threat, releases a compound called histamine.

Histamine is a pro-inflammatory compound that leads to many symptoms of allergies. In this case, you'll spot redness and rashes in the area where the contact with the setae was made.

So the second symptom you're most likely to see is redness, itching, swelling, or any other type of localized skin reaction. In some cases, like when stung by a southern flannel moth caterpillar, you may also spot vesicles or sacs filled with fluid.

The pain lasts somewhere between an hour to a couple of days depending on which stinging caterpillar was involved. There are several instances of caterpillar encounters where things got severe. People even got hospitalized after being stung by these tiny creatures.

First of all, how we react to toxic compounds depends on how sensitive our skin is. People with sensitive skin are likely to face drastic consequences.

For example, a woman in Florida was rushed to the hospital after she complained of a sharp pain stabbing through her body. The pain was so intense that even morphine did not help. Doctors said it was most probably the puss caterpillar.

In another case where a five-year-old girl from Texas was stung by the same puss caterpillar, she was rushed to the hospital and given immediate medical attention. Her arm went numb after the contact. Things got worse with her entire body going numb and shutting down, eventually affecting her internal organs.

Buck moth caterpillar sting symptoms also include labored breathing. People have also faced problems with breathing after coming in contact with stinging caterpillars. If somehow the hairs or spines make it through the nose down towards the lungs, it can cause labored breathing. If the hair comes in contact with the eyes, it can lead to conjunctivitis.

Thus moth caterpillars' hairs and stings can lead to reactions and sickness but rarely kill someone.

How To Treat Caterpillar Stings

After you spot any of the symptoms mentioned above, you must be quick in your reaction. Your first job should be to get immediate medical attention, especially when there are children involved or those with sensitive skin.

If you can arrange first aid, that's sufficient in most cases because the sting reaction isn't likely to be severe unless stung by a buck moth or flannel moth caterpillar.

First, you need to grab some tape from the first aid box. With the sticky part of the tape facing towards the bitten area, rub it across.

The objective is to pluck out all the spines and hairs that might have got stuck on the surface. If these spines stay put, they may increase the itching and swelling. So, repeat the tape therapy several times with fresh pieces of tape.

Next, you need to use soap and water to wash the area that's affected. It may offer some relief and get rid of poison compounds. You should wash the area several times. Then, opt for hydrocortisone cream that can treat rashes and itching. Such creams are readily available in all pharmacies and general stores.

The last option is applying an ice pack. Ice can cool down the surface and reduce irritation, swelling, and burning sensations. Keep the pack attached to the affected area for 10-15 minutes. Then recheck the conditions to see if the swelling has reduced. If it has, then you've got things under control.

While treating the sting, proceed in the same order as discussed above. First, use the tapes, then wash the affected area, then apply the hydrocortisone cream, and finally apply the ice pack. If even a single spiny extension remains on the surface, it will cause more problems.

From the ingredients in your kitchen, you can use baking soda. Prepare a paste of baking soda with water and apply it to the surface.

The baking soda paste will provide instant relief from a caterpillar rash. If you fail to get things under control and symptoms get severe, make arrangements to get to the hospital before your health deteriorates.

Diagnosis Of A Caterpillar Sting

It's hard to diagnose a fuzzy caterpillar sting because they're easily mistaken for something else. Thus, there's a high chance of misdiagnosing the sting of a caterpillar.

The first step of diagnosis is determining whether caterpillars are found in your area and of which family. For example, stinging caterpillar types like buck moth and flannel moth caterpillar are common in Texas.

These moths mostly stay in oak trees and under plants' foliage. Therefore, if you live in Texas and spot rashes after returning from a garden area, chances are high that it's the sting of a caterpillar.

If the symptoms resemble the ones discussed above, it should confirm the case. Search on the internet to determine which type of stinging caterpillars are found in the area. Determine which moth caterpillars, buck moth caterpillars, flannel moth caterpillars, or the saddleback have stung you.

Saddleback moths are distinctive from others because of their green patch, thus making it easier for you to confirm. Also, search for the trees and plants that are common in your area. Then proceed with the available remedies to get things under control.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for 'Stinging caterpillars' then why not take a look at 'Bee life cycle' or 'Caterpillar facts'?