# Recurrent Intestinal Worm Reinfestation - Category: infectious - Review status: reviewed (every claim checked against a document named on this page) - Sources: CDC Enterobiasis Guidelines 2020 · Egyptian National Drug Formulary - Antimicrobial 2023 (mebendazole monograph) · MSF Essential Drugs 2024 - albendazole (oral), indications and dosage (msf-essential-drugs-2024.txt, page 27) - Verified date: 2026-08 ## Verified against - Egyptian National Drug Formulary - Antimicrobial 2023 (mebendazole monograph) - MSF Essential Drugs 2024 - albendazole (oral), indications and dosage (msf-essential-drugs-2024.txt, page 27) ## Treatment metadata - Mebendazole — 100 mg — oral.solid - Albendazole — 400 mg — oral.solid ## Complete treatment card ```text RECURRENT INTESTINAL WORM REINFESTATION Sources: CDC Enterobiasis Guidelines 2020 · Egyptian National Drug Formulary - Antimicrobial 2023 (mebendazole monograph) · MSF Essential Drugs 2024 - albendazole (oral), indications and dosage (msf-essential-drugs-2024.txt, page 27) Review status: REVIEWED against 2 sources listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - About a third carry the worm and feel nothing at all - Itching around the anus is the leading complaint [itching] - Unrelenting itch breaks sleep and can end in insomnia [insomnia · itching] - Genitourinary infection in girls and women is described, as is watery diarrhoea [diarrhoea] - Abdominal pain, and even appendicitis, can follow worms blocking or inflaming the appendix [abdominal pain] SIGNS - what you find (3) - Redness of the perianal skin follows the itching and the scratching [itching · redness] - Scratch sites may turn red and warm from a shallow bacterial infection - Fine thread-like worms are sometimes visible around the anus with no lens at all TESTS (7) - Diagnosis is by cellophane tape or a paddle pressed to perianal skin and read under a microscope - Ova measure 50 by 30 microns and lie flattened on one side; whole worms may show instead - Females run 8 to 13 mm long and males 2 to 5 mm - Sample early in the morning, when the yield is highest - Only five straight negative mornings exclude it - Stool microscopy does not answer the question, the worms reaching stool only now and then - Stool is still sometimes analysed to exclude other causes IF NOT THIS - what else fits (5) - Pruritus ani - Pruritus vulvae - Atopic dermatitis - Perirectal abscess - Cellulitis of the skin there Source StatPearls "Enterobius Vermicularis" - disease-level clinical article Status traced to the source above 1. MEBENDAZOLE [1st line] Adult 100 mg single dose, REPEAT a second 100 mg dose after 14 days - Single dose repeated at 14 days Peds 2 years and over: 100 mg single dose; repeat in 2 weeks (Treatment of patients ≥2 years of age: 100 mg as a single dose; repeat in 2 weeks) Source Egyptian National Drug Formulary - Antimicrobial 2023 (mebendazole monograph) Why Repeat dose at 14 days is essential to kill newly hatched ova and prevent household cycle reinfestation Caution HOUSEHOLD RULE: Treat ALL household members simultaneously regardless of symptoms. Repeat 2nd dose strictly 14 days later (first dose kills adult worms, second dose kills newly hatched eggs). The Egyptian formulary gives mebendazole for adults, adolescents and children over 2 years. Use below 2 years is outside that range - weigh it deliberately rather than by habit. Experience in children <2 years is limited; convulsions have been reported in children <1 year. Egypt MEBAMOX 100MG 6 TAB. EL NASR 3.25 EGP (0.54/unit) PENTALMIN 100MG 6 TAB. PHAROPHARMA 3.50 EGP (0.58/unit) VERMIN 100MG 6 TAB. MEMPHIS 8.00 EGP (1.33/unit) ANTIVER 100MG 20*6 TABS. ALEXANDRIA 200.00 EGP (33.33/unit) ANTHELMIN 100MG/5ML SUSP. 30ML PHARCO 3.50 EGP -> ? strength differs, ? different route - not oral solid PERMAX 100MG/5ML SUSP. 30ML EIPICO 10.00 EGP -> ? strength differs, ? different route - not oral solid 2. ALBENDAZOLE [2nd line] Adult 400 mg orally as a single dose; a second 400 mg dose may be given after 2-4 weeks - Single dose, optionally repeated once at 2-4 weeks Peds Age restriction: minimum 6 months (Child over 6 months and 10 kg or more: 400 mg as a single dose, as for adults. Child over 6 months but under 10 kg: 200 mg as a single dose. Not below 6 months. Tablets are to be chewed or crushed.) Source MSF Essential Drugs 2024 - albendazole (oral), indications and dosage (msf-essential- drugs-2024.txt, page 27) Why Alternative to mebendazole for recurrent enterobiasis where the household cycle keeps re-seeding. MSF Essential Drugs lists enterobiasis (Enterobius vermicularis) among albendazole's indications and gives the repeat dose directly: the first dose kills the adult worms, the repeat catches what has hatched since. Caution HOUSEHOLD RULE: Treat ALL household members simultaneously regardless of symptoms. The repeat dose is what prevents reinfestation. For enterobiasis, MSF Essential Drugs 2024 allows a second dose 2 to 4 weeks later. That is a different interval from the 14 days used for mebendazole above - each drug keeps its own source's interval. Do not give to a child under 6 months (MSF Essential Drugs 2024). Avoid during the first trimester of pregnancy. No contra-indication in breast-feeding. Not for a patient with ocular cysticercosis. May cause gastrointestinal upset, headache or dizziness; seizures have been reported where neurocysticercosis was present but undiagnosed. The Egyptian formulary's albendazole monograph lists only hydatid disease and neurocysticercosis, and its doses are for those - do not read the 15 mg/kg/day figures across. The dose above is MSF's, for enterobiasis. Egypt ALBENDAZOLE 400 MG 6 TABS PHARMA CURE P... 46.00 EGP (7.67/unit) ANTIZOLE 100MG/5ML SUSP. 30ML ALEXANDRIA 19.00 EGP -> ? strength differs, ? different route - not oral solid ALZENTAL 20MG/ML SUSP. 20ML EIPICO 21.00 EGP -> ? strength differs, ? different route - not oral solid Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)