Hymenolepis nana is a cestode parasite commonly known as dwarf tapeworm. The diagnostic features of this family are: scolex armed with one circlet of five hooks; one to three large testes and sacciform uterus.The scolex is knob like in shape, has a rostellum with hooklets and four suckers. The segments are wider than they are long.
It is found throughout the world, more frequently in warm climate and temperate zones, commonly infects both rodents and human beings with school-aged children being more frequently infected. Light H. nana infections are usually asymptomatic, whereas heavy infections with more than 2,000 worms can induce a wide range of gastrointestinal symptoms and allergic responses including chronic urticaria, skin eruption, and phlyctenular keratoconjunctivitis, as well as abdominal pain and diarrhoea.