[Bed bugs, lice and fleas-an up-to-date overview of diagnosis, treatment and prevention].

Despite high standards of hygiene, ectoparasites remain a significant issue in dermatology. Bedbugs (Cimex lectularius) have become significantly more prevalent worldwide over the past two decades, whilst head lice infestation (Pediculus humanus capitis) remains one of the most common parasitic infections in children. Pubic lice (Pthirus pubis) are predominantly transmitted sexually. Body lice (Pediculus humanus corporis) are rare in Central Europe, but remain of infectious disease significance as vectors of Rickettsia prowazekii, Bartonella quintana and Borrelia recurrentis. Flea bites in humans are now predominantly caused by the cat flea (Ctenocephalides felis). The clinical spectrum ranges from asymptomatic cases through papular and urticarial reactions to bullous arthropod reactions and bacterial superinfections. Diagnosis is based on medical history, clinical findings and the direct detection of parasites, nits or characteristic environmental traces. Dermoscopy facilitates the differentiation of live parasites from nits and pseudonits, particularly in cases of pediculosis. Treatment for lice infestations comprises topical pediculicides and physically acting preparations. In the case of bedbug and flea infestations, consistent environmental control measures are crucial for long-term therapeutic success; in the case of flea infestations, concurrent veterinary treatment of infested pets is also essential. This article summarises the current state of knowledge regarding the epidemiology, biology, clinical presentation, diagnosis, treatment and prevention of these medically important ectoparasitic infestations.