Strongyloidiasis, Man

Strongyloidiasis is produced by Strongyloides stercoralis , a parasite of humans, dogs, and cats, and occasionally other species, normally from other hosts. Larvae penetrate the skin and give rise to dermatitis at the site of entry. They then migrate either though the lung, where they may cause allergic pneumonia, or by other pathways to the intestine where they become adults. The females most commonly reach adulthood in the duodenum and upper jejunum and enter the mucosa, to lay eggs. Mucosal inflammation, and later atrophy, leading to malabsorption and emaciation, are the consequence of heavy infections. The larvae, which are soon released from the thin-walled eggs, are shed in the stool. However, some reenter the mucosa or the perianal skin maintaining a chronic infectionwhich is characterized by fleeting urticarial rashes on the abdomen, buttocks, thighs, and often perianally. In immunosuppressed hosts this autoinflection can lead to a marked increase in tissue invasion by larvae...