Health Tips

Image credit: Alvesgaspar, CC BY-SA 4.0, via Wikimedia Commons

Does this insect look familiar to you? Yes, it is the notorious rove beetle, and its ‘bite’? No joke.

Also called “Charlie Ants”, rove beetles are a household pest no stranger to Malaysians, especially during the rainy season. As the insects move quickly, you might only catch glimpses of them. 

Finding rove beetles

Adult rove beetles are typically smaller than 2 cm in length. Commonly, they are black or brown with slender bodies and short front wings. You can distinguish these pests from other beetles by the way they angle their abdomens upward when they run or are startled. 

During heavy rains or floods, rove beetles may migrate to drier areas. During the daytime, rove beetles can be seen crawling around on the ground, with their wings hidden, and can resemble ants. Adult rove beetles are predators of other insects and at night are frequently encountered around light sources. 

Image credit: US Army Public Health Command (US Army Center for Health Promotion and Preventive Medicine USACHPPM, Public domain, via Wikimedia Commons

Beware of rove beetles ‘bites’!

If you have been ‘bitten’ by a rove beetle before, you know what an agony that might be. But there’s a clear misunderstanding here: rove beetles actually don’t bite or sting. 

As a matter of fact, rove beetles cause Paederus dermatitis by releasing a fluid containing a toxin called paederin. This usually happens when you crush the beetle– the toxin is released and absorbed by your skin. The beetle can be crushed if you swat it like a fly or mosquito or if it collides with you at speed (such as bare skin on a motorbike). As a result, you may experience the following:

• Reddening of skin.

• ‘Kissing lesions’ where two adjacent flexural surfaces come together

• A painful irritation and ‘burning’ sensation, accompanied by itching.

• Extensive pustules and blistering of skin after 4 days of exposure to the toxin.

• The affected areas remain irritated, blistered and sore for 10 days. Toxin on the hands, or exposure near body joints, can spread toxin to other areas of the body and to others.

Kissing lesions in Paedarus dermatitis. Image credit: DermNetNZ.org via CC BY-NC-ND 3.0 NZ

Paedarus dermatitis, two photographs, one showing "kissing" lesion where pederin was transferred to two skin surfaces that touch each other. Image credit: US Army Public Health Command (US Army Center for Health Promotion and Preventive Medicine USACHPPM, Public domain, via Wikimedia Commons

Paederus dermatitis happens because the paederin released by the rove beetles into our bloodstream can unleash a series of biochemical reactions, such as a release of epidermal proteases and a loss of intercellular connection, inhibiting protein synthesis, DNA synthesis, and mitosis. Fun fact: The manufacture of paederin is largely confined to the female rove beetles.

Don’t overlook it

People may have different responses after exposure to the toxins. It depends upon its concentration, duration of exposure, and individual characteristics. Another important point, where the toxins go is very important. If you accidentally transfer the toxins on hands to genital areas such as penis, you may experience balanitis, i.e. inflammation of the glans of the penis; if the toxins are spread to the eyes, you may experience ‘Nairobi eye’, a type of conjunctivitis.

If paederus dermatitis is not treated properly, it can result in some serious complications, including infection, exfoliation and ulceration (sometimes requiring hospitalisation), postinflammatory hyperpigmentation and scarring. 

What to do if you develop paederus dermatitis?

If you are exposed to rove beetle toxin, wash the affected area immediately with soapy water, and then use cold compresses, take antihistamines if you have them, or apply aloe vera to alleviate the symptoms on exposed areas. If your skin seems to develop severe reactions to the toxins, consult a healthcare professional immediately. The treatment for paederus dermatitis include:

• A topical steroid cream to reduce irritation and itchiness

• Tincture of iodine can help neutralise the paederin toxin and act as an antiseptic 

• Soothing creams containing calamine, camphor, and topical anaesthetic can provide relief of pain and itching.

• Oral antibiotics (eg, ciprofloxacin) if the doctor suspects any secondary bacterial infection

Protect yourself from the effects of rove beetles

It was known that rove beetles usually lived in paddy fields and when these fields were harvested and burnt, they would have sought refuge at the condominium. So sometimes you can’t really blame these little guys for appearing at your home. With that being said, there are several ways to protect yourself from them so that both you and the rove beetles can live peaceful lives, separately:

• Just don’t touch them. 

• ‘But sometimes they just couldn’t leave me alone!’ We hear you. Blow or wash beetles off if they land on your skin. If that is not possible, wear gloves or use tissue paper to remove them, then throw them away immediately.

• Minimise lighting in infested areas at night. 

• Wear long-sleeved and long-legged clothing to minimise exposed skin. 

• If you are camping, keep insect screens closed on tents to keep the beetles out of bedding. 

• If a rove beetle is accidentally crushed against the skin, immediately wash the affected area with soap and water. The toxin slowly penetrates the skin. Washing shortly after exposure will remove much of the toxin before it has time to harm the skin.

A word from Doc2Us

If you have any questions related to paederus dermatitis, you can consult our professional doctors and healthcare professionals on Doc2Us. Doc2Us is a mobile application that allows you to talk to a doctor or any healthcare professionals via text chat at any time and from anywhere.  For better communication, you can even send our online doctor images or voice messages related to your medical inquiry.

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Disclaimer: As a service to our users and general public, Doc2Us provides health education contents. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

References

1. Orkin Canada - Rove Beetles

2. DermNet NZ - Paederus dermatitis

3. Ali, A., Kathirvel, S., T, D., P, S., K, B., S, P., M, S., Innocent, J. and S, V., 2013. A study on Paederus dermatitis outbreak in a suburban teaching research hospital, Kanchipuram, India. Medicine Science | International Medical Journal, 2(3), p.764.

4. Kumar, A. and Karthikeyan, K., 2017. Paederus dermatitis. Indian Journal of Dermatology, Venereology and Leprology, 83(4), p.424.

5. NSW Government - Rove Beetles

6. American Osteopathic College of Dermatology - Paederus dermatitis

Cover image credit: Alvesgaspar, CC BY-SA 4.0, via Wikimedia Commons

Written by

Ms Joyce Toh