A case report from Virginia (

) illustrates several medical truisms. Firstly, if you don’t remember it you won’t diagnose it. Secondly, non-diagnosis may lead to a farcical situation in which you continue to scratch your head, the patient (in this case) continues to scratch her body, and unnecessary investigations and attempts at treatment may ensue. Thirdly, the patient may, in the end, get the answer from the internet.

A 10 year old girl in Virginia had had a pruritic rash consisting of pink papules and macules on her limbs, buttocks, chest, and neck for 3 months. She had had two punch biopsies and her treatments had included several short courses of oral steroid, antihistamines, antibiotics, and topical permethrin, antibiotic ointments, and steroid creams. The biopsies showed a lot of eosinophils and arthropod bites were thought to be the most likely cause. At this point the child’s mother found some information about bedbugs on the internet. She examined the child’s bed with a torch in the middle of the night and recovered several small brown bugs, which were identified as bedbugs (Cimex lectularius). A pest control service was called in and the child recovered.

Bedbugs were common until the 1940s when they were virtually eradicated by use of dichlorodiphenyltricholoroethane (DDT). Since 1995 increases in bedbug infestation had been reported in the USA, the UK, and Brazil. Bedbugs live in dry corners (mattresses, furniture, floorboards, wallpaper pockets) during the day and emerge at night to feed on human blood. They have never been shown to be vectors for blood-borne disease. Children bitten by bedbugs are most likely to present with papular urticaria.

The recent increase in bedbugs has been attributed to increased air travel and to changes in pesticide management that have eliminated some of the bedbug’s predators such as cockroaches, ants, and spiders. Eradication may be difficult. The services of a professional pest-killing agency may be needed.