An Adult Loa loa Worm in the Upper Eyelid: An Atypical Presentation of Loiasis in the United States

Abstract

Purpose. To report a case of ocular involvement of Loa loa parasite. Observations. We present a rare case report of a Loiasis diagnosed in the United States from a patient presenting with subcutaneous migration of an adult worm within an eyelid who was found to have systemic disease with microfilaria in his blood. This is the second report in the United States and the eighth case in published literature worldwide. Conclusions and Importance. Due to the relatively mild disease course, Loiasis is relatively ignored in public health in low resource health districts. Understandably, the focus of public health in endemic areas must focus on basic health needs like malnutrition and diseases that entail a greater disease burden. As globalization has increased the amount of trade of physical goods, the effect of immigration also has implications for the spread of infectious disease. Medical practitioners in the United States should be aware of endemic diseases from foreign lands.

Living parasite in the eyelid

“…10 Literature reported two cases of Loa loa macrofilaria diagnosed in United states. 4 Total eight similar cases are reported in the literatures. 10,11 This case represents the second case of periocular subcutaneous Loa loa macrofilaria of the eyelid in Bangladesh.…”

“…Loiasis is a filarial disease caused by the nematode Loa loa which is an undertreated infectious disease and restricted in Central and Western Africa. [3][4][5] It is transmitted to humans by the bites of mango flies or deerflies (Chrysops silica and Chrysops dimidiate), which introduce larvae into the subcutaneous tissues of human. Macrofilaria migrate in the subcutaneous and deep connective tissues, and the microfilariae are found in the blood.…”

“…The adult worm is about 30-70 millimeters in length and 0.3-0.5 mm in diameter. 4,5,7 The literature reported that adult worms may survive in human tissue for up to 21 years. 8,9 The first clinical presentation may appear as soon as 5 months of post infection.…”

“…1 Surgery is the treatment of choice for eyelid and subconjunctival parasitic lesion. 2,3 The first line anti-parasitic medication like diethylcarbamazine (DEC) to kill both microfilaria and macrofilaria, 4,5 and the second line treatment include albendazole or ivermectin, both have limited efficacy on adult worms. 6 Oral steroid may be used in combination with anti-parasitic drug to reduce inflammation and allergic reaction to parasite and adverse effects of anti-parasitic medication.…”