Loiasis

- filarial infection caused by Loa loa (African eye worm)
- transmitted by Chrysops fly
- adult parasites live in subcutaneous tissue
- microfilariae circulate in blood with a diurnal periodocity
- subconjunctival migration of an adult worm
- Calabar swelling (localised area of angioedema and erythema developing on extremities) is thought to result from a hypersensitivity reaction to adult worm antigens
- definitive diagnosis requires the detection of microfilariae in peripheral blood or isolation of adult worm from the eye or subcutaneous biopsy
- eosinophilia suggest the diagnosis
- diethylcarbamazine (DEC) for 3 weeks