Crawling alarm in bed

In neighbouring France, bedbugs are responsible for a proper epidemic. The pests can be found in accommodation and transport. Even in leisure facilities such as cinemas. Some also find their way to Germany as holiday souvenirs.

The bedbug Cimex lectularius from the flat bug family (Cimicidae) was almost extinct in Germany. However, travelling has enabled the parasites to make a comeback. The parasites feel particu-larly at home in places where many people come together: in hotels, shared accommodation, hospitals or means of transport such as buses and trains.

An adult bedbug is 4 to 5 mm long and can reach a length of 9 mm when fully engorged. The in-sects are more difficult to recognise at the beginning of their development, as the juvenile stages are significantly smaller and lighter in colour. Until they have reached their final size, bedbugs moult five times, each time requiring a blood meal. The adult parasites are rust-red to dark brown in colour and resemble an apple seed. However, they are not often seen: bedbugs are nocturnal, very agile and know how to hide. During the day, the little creatures linger in cracks in bed fra-mes, under mattresses, behind skirting boards, in furniture crevices or behind pictures. At night, body heat and vapours such as carbon dioxide (CO2) attract the parasites.

They need a blood meal every three to five days. Adult animals can also survive periods of star-vation of up to eight months. The parasites suck for between five to ten minutes and usually bite several times until they hit a blood vessel. The bites are in a typical row-like arrangement, the so-called »bug street« or ungrouped. When sucking, the insects secrete saliva. This not only contains anticoagulant substances, but also anaesthetic and haemolytic components as well as sensitising proteins. Due to the anaesthetic effect, many people do not notice the lesions at first. These are preferably found on parts of the body such as the arms, shoulders, legs and face that are uncovered during sleep.

There is little reason to fear that the parasites transmit diseases when sucking. However, the cocktail of substances in the saliva leads to unpleasant skin reactions that characterise the clini-cal picture of cimicosis. The severity of the symptoms depends on the degree of sensitisation of the stung person. Those who are less sensitised develop 1 to 2 cm large wheals with a haemorr-hagic spot in the centre. In highly sensitised people, efflorescences can be up to 20 cm in size and urticarial exanthema can develop with very many bites. Severely itchy papules can persist for several days and tempt the patient to scratch. Bacterial superinfections and skin inflammations are possible. In severe chronic infestations, some patients develop anaemia in addition to the skin symptoms.

If itchy spots are unclear, allergic reactions, for example to food, or illnesses such as urticaria or chickenpox should be ruled out. In the case of bedbug bites, these will heal within one to two weeks if they are uncomplicated. The pharmacy team can recommend symptomatic antiprurigi-nosa (anti-itch) such as polidocanol in Lotio alba aquosa and antiseptic topicals. If the symptoms are severe, short-term topical treatment with glucocorticoids such as betamethasone may be ne-cessary. Scratched wheals can become inflamed and require antibiotic therapy. Some people have an allergic reaction to the secretion of bedbugs. In this case, oral antihistamines can help.