# Loiasis (Loa Loa Infection) - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Filariasis - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK556012/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class AD24.07 - condition scope only, no dose · Egyptian National Drug Formulary - Antimicrobial 2023 (diethylcarbamazine monograph, p28) - Verified date: 2026-08 ## Verified against - Loiasis (Loa Loa Infection) - disease-level clinical article (loiasis-clinical.txt) - Egyptian National Drug Formulary - Antimicrobial 2023 (diethylcarbamazine monograph, p28) ## Treatment metadata - Diethylcarbamazine — 100 mg — oral.solid - Referral & safety-netting (no drug therapy) ## Complete treatment card ```text LOIASIS (LOA LOA INFECTION) Sources: Filariasis - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK556012/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class AD24.07 - condition scope only, no dose · Egyptian National Drug Formulary - Antimicrobial 2023 (diethylcarbamazine monograph, p28) Review status: REVIEWED against Loiasis (Loa Loa Infection) - disease-level clinical article (loiasis-clinical.txt), Egyptian National Drug Formulary - Antimicrobial 2023 (diethylcarbamazine monograph, p28) (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - Most people infected with Loa loa have no symptoms at all - Transient, non-red swellings under the skin (Calabar swellings) occur on the face or limbs from a hypersensitivity reaction to the moving worm - Pain, itching, or hives can come before a Calabar swelling appears, and the swelling usually settles within 2 to 4 days [itching · urticaria] - Patients sometimes notice a worm crossing under the conjunctiva of the eye, with brief swelling and inflammation - Calabar swellings sit most often near a joint, and they are a hypersensitivity reaction to the worm moving, not the worm itself SIGNS - what you find (2) - Eye symptoms typically settle once the worm has migrated out, and crossing the conjunctiva usually takes 10 to 20 minutes - Less common complications include joint inflammation, heart muscle fibrosis, and brain/meninges involvement TESTS (5) - Marked eosinophilia, often above 3000 cells/uL, and raised IgE are common lab findings in filarial infection - For L. loa, blood is best drawn between 10 am and 2 pm because its microfilariae circulate by day - An antibody test against the recombinant LLSXP-1 antigen is L. loa specific but is currently research-only - Heavy L. loa microfilaraemia can give a false-positive circulating antigen test intended for W. bancrofti - Diagnosis rests on finding a migrating adult worm under the skin or conjunctiva, or microfilariae in the blood IF NOT THIS - what else fits (8) - Bacterial lymphangitis - Cutaneous larva migrans - Gnathostomiasis - Idiopathic hypereosinophilic syndrome - Strongyloidiasis - Systemic vasculitis - Other zoonotic filarial infections such as Dipetalonema - Tuberculosis Source StatPearls "Filariasis" - disease-level clinical article Status traced to the source above Rx: Antiparasitic | Main treatment ANTIPARASITIC 1. DIETHYLCARBAMAZINE [1st line] Adult 8-10 mg/kg/day in 3 divided doses x 21 days; repeat courses may be needed for cure Peds 8-10 mg/kg/day (Children and adolescents: 8-10 mg/kg/day in 3 divided doses for 21 days, the same rule as for adults.) 3kg -> 24-30 mg/day 4kg -> 32-40 mg/day 5kg -> 40-50 mg/day 6kg -> 48-60 mg/day 7kg -> 56-70 mg/day 8kg -> 64-80 mg/day 9kg -> 72-90 mg/day 10kg -> 80-100 mg/day 11kg -> 88-110 mg/day 12kg -> 96-120 mg/day 13kg -> 104-130 mg/day 14kg -> 112-140 mg/day 15kg -> 120-150 mg/day 16kg -> 128-160 mg/day 17kg -> 136-170 mg/day 18kg -> 144-180 mg/day 19kg -> 152-190 mg/day 20kg -> 160-200 mg/day 21kg -> 168-210 mg/day 22kg -> 176-220 mg/day 23kg -> 184-230 mg/day 24kg -> 192-240 mg/day 25kg -> 200-250 mg/day 26kg -> 208-260 mg/day 27kg -> 216-270 mg/day 28kg -> 224-280 mg/day 29kg -> 232-290 mg/day 30kg -> 240-300 mg/day 31kg -> 248-310 mg/day 32kg -> 256-320 mg/day 33kg -> 264-330 mg/day 34kg -> 272-340 mg/day 35kg -> 280-350 mg/day 36kg -> 288-360 mg/day 37kg -> 296-370 mg/day 38kg -> 304-380 mg/day 39kg -> 312-390 mg/day 40kg -> 320-400 mg/day 41kg -> 328-410 mg/day 42kg -> 336-420 mg/day 43kg -> 344-430 mg/day 44kg -> 352-440 mg/day 45kg -> 360-450 mg/day 46kg -> 368-460 mg/day 47kg -> 376-470 mg/day 48kg -> 384-480 mg/day 49kg -> 392-490 mg/day 50kg -> 400-500 mg/day Source Egyptian National Drug Formulary - Antimicrobial 2023 (diethylcarbamazine monograph, p28) Why The formulary names treatment and prophylaxis of loiasis as this drug's indication and gives the CDC regimen of 8-10 mg/kg/day in three divided doses for 21 days, for adults and for children alike. The disease article cited on the card gives the same figure and adds the reason it cannot simply be prescribed: in a patient carrying a heavy microfilarial load the drug can cause encephalitis and shock, so the blood microfilarial count decides the approach before the first tablet. Caution COUNT THE MICROFILARIAE BEFORE TREATING. The cited article gives 8,000 microfilariae/mL as the threshold: below it, this regimen; above it, albendazole 200 mg twice daily for 21 days first to bring the load down, with apheresis for very high loads. Some experts set the threshold lower, at 2,500/mL, and use ivermectin 150 mcg/kg between 2,500 and 20,000. CONTRAINDICATED IN ONCHOCERCIASIS - the formulary's only listed contraindication. Giving this drug to someone co-infected with river blindness triggers a severe inflammatory reaction. FOR A PATIENT WITH MICROFILARIA IN THE BLOOD the formulary offers a dose-escalating start instead: 50 mg once on day 1; 50 mg three times on day 2; 100 mg three times on day 3; then 9 mg/kg/day in 3 divided doses from day 4 to the end. Test for co-infection with onchocerciasis and with loiasis itself before treating anyone from an area where either is endemic. Both diethylcarbamazine and ivermectin can cause a fatal encephalopathy in loiasis. Prophylaxis, where exposure continues, is 300 mg once weekly. Egypt no Egyptian brand matched - prescribe by generic name MAIN TREATMENT 2. REFERRAL & SAFETY-NETTING (NO DRUG THERAPY) [1st line] Adult Filarial infection transmitted by the Chrysops fly of Central/West African forests, not found in Egypt. Relevant only in a patient with a matching travel history presenting with migrating (Calabar) swellings or a worm crossing the eye; treatment (diethylcarbamazine) can trigger severe reactions in heavily infected patients and needs specialist supervision. - Refer Peds Children follow the same pathway: recognise and refer. No primary-care medicine is implied. Source No dose - referral pathway, no medicine given in primary care Why Filarial infection transmitted by the Chrysops fly of Central/West African forests, not found in Egypt. Relevant only in a patient with a matching travel history presenting with migrating (Calabar) swellings or a worm crossing the eye; treatment (diethylcarbamazine) can trigger severe reactions in heavily infected patients and needs specialist supervision. Caution Not endemic in Egypt. Relevant to a returning traveller or an imported case; consider the travel history before anything else. The drug rows above are what the treating service gives. They are here so that the referral is an informed one and so the GP can recognise the regimen the patient comes back on - not as permission to start it without the referral. RED FLAG - Both DEC and ivermectin can cause potentially fatal encephalopathy in patients with loiasis. RED FLAG - A worm visibly crossing the conjunctiva, Calabar swellings after travel to Central or West Africa, or a very high microfilarial load before treatment, which carries a risk of encephalopathy with diethylcarbamazine and must be specialist-managed. 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)