Beetling about in Sudan

Frontier Medical medics working in Sudan were recently alarmed at the number of patients presenting with what appeared to be symptoms of severe sunburn - redness, peeling skin, blisters and other lesions - frequently leaving pigmented scars that lasted for some months.

Consultation with the Topside team revealed that, although the lesions were a type of burn, the culprit was more likely to be earthly than solar, caused by an acid-like substance, Pederin, a toxic amide peculiar to a species of the Paederus or 'Rove' beetle.

Found in Africa, Asia and South America and more colloquially known as the 'Acid Ant' or 'Champion Beetle', it's the female of the species that manufactures Pederin. Although otherwise harmless, she will leave her mark and something to remember her by if unnecessarily crushed.

Pigmented scars

Swatting a female Paederus when she's settled on your exposed skin can cause a range of symptoms, but unfortunately these don't present themselves until at least 24 hours later, often causing the toxin to be spread inadvertently to the eyes and other areas. Mild cases can leave just a slight redness, but more normally there are blisters at around 48 hours which may dry out and develop a crust-like covering over the next seven days, finally leaving pigmented scars that can last for several months. These wounds are often elongate in shape, caused when the patient smears the crushed beetle juice across the skin. Occasionally, if a patient has severe exposure, blistering may last for many months exacerbated by additional symptoms such as fever, headaches and vomiting.

Education is probably the best tactic in preventing future Pederin injuries. Pederin is only released when a beetle is damaged, so learning to identify the beetle and to remove it safely is a first step in self-defence, perhaps by blowing it away or encouraging it to move on to a piece of paper, fabric or other surface. The use of screens and bed nets will reduce the likelihood of inadvertently squashing a beetle during the night Check bedding before sleeping If significant numbers of beetles are present, consider whether local vegetation is providing a breeding ground

If Pederin does come into contact with the skin, it's best treated immediately by washing with soap and water, then the removal of any crusts and the application of a thin coat of antibacterial ointment and a dressing for 24 - 48 hours.

Occasionally mass outbreaks of dermatitis are caused through local infestations of the Paederus beetle. Because they like moisture, it's excessive rain rather than too much sunshine that exacerbates the problem, with Paederus numbers increasing after an exceptionally wet year. A contribution to the medical journal, The Lancet, has suggested that given the right conditions, the impact of the Paederus beetle could reach biblical proportions. It suggests that, of the ten plagues to strike down the Egyptians (Exodus 7-12), the Paederus beetle was responsible for three.

Living as they did in the marshy banks of the Nile and scavenging on tadpoles and carrion, piles of fetid frogs (plague number two) forced from the Nile when the waters turned to poison (plague number one) would have provided a veritable feast for a hungry Paederus beetle. It could be expected that numbers would definitely flourish. Which brings us to the flies (or was it beetles?), the third and fourth plagues, when "dense swarms infested Pharaoh's house" and the houses of the Egyptians and herds of animals died. And this was rapidly followed by the sixth plague, an outbreak of boils and blisters, bursting out all over the beleaguered Egyptians, coincidentally only just a few days later.

Champion?