tender hepatomegaly Severe infection with the intestinal form of the disease may result in development of portal hypertension, ascites, esophageal varices, and hematemesis The drug of choice is praziquantel (dosing varies depending on the species) and the treatment must be repeated approximately to months later due to failure of the medication to kill developing worms Schistosomal dermatitis (swimmer’s itch) does not require therapy Paradoxical inflammation after antiparasitic therapy is common and can be treated with systemic corticosteroids Standard precautions exist for isolation of infected patients Soil Helminthic Infections A number of helminthic infections cause human disease Most are transmitted through the fecal–oral route, though in some cases helminths can penetrate intact skin The most common helminthic infections are Enterobius vermicularis (pinworms), Trichuris trichiura (whipworm), Ascaris lumbricoides (roundworm), Ancylostoma (hookworm), cutaneous larva migrans (CLM) (sandworm), and Strongyloides Most infected individuals are asymptomatic Clinical manifestations are strongly related to the intensity of the infection and worm burden Some infections result in anemia or impaired growth and cognition Diagnosis is usually made via visualization of larvae in the stool The clinical manifestations, diagnosis, and treatment are summarized in e-Table 94.24 Most can be treated with either albendazole or mebendazole; albendazole is typically more tolerable for patients in terms of taste and side effects The albendazole dose is 400 mg for both children and adults A single-dose regimen is the recommended treatment for Ancylostoma, Ascaris, and Enterobius, whereas Trichuris requires a 3-day course and Strongyloides a 7-day course with twice-daily dosing SKIN/SOFT TISSUE INFECTIONS Dermatologic conditions are common among persons who have recently traveled ( Table 94.21 ) Urticaria is common, and can be caused by Strongyloides stercoralis, scabies, schistosomiasis, onchocerciasis, or insect bites Insect bites (such as bedbugs and fleas) are the most common cutaneous finding in the returning traveler The most common cause of ulcers is pyoderma, caused by streptococci and staphylococci, but can also be caused by cutaneous leishmaniasis Eschars may be seen in rickettsial disorders such as Mediterranean spotted fever, scrub typhus, and African tick typhus Burrowing lesions can be caused by botflies (myiasis) and fleas (tungiasis) Leishmaniasis