ARCH SOC ESP OFTALMOL 2007; 82: 55-58 SHORT COMMUNICATION

LOIASIS. APPROACH TO A FORM OF OCULAR PARASITOSIS

LOIASIS. APROXIMACIÓN A UNA FORMA DE PARASITOSIS OCULAR

LÓPEZ-RODRÍGUEZ I1, DE-LA-FUENTE-CID R1, CARNERO-LÓPEZ JM1, CORDIDO-CARBALLIDO M2, ZÚÑIGA-RODRÍGUEZ C3

ABSTRACT RESUMEN

Case report: We present the case of a man from Caso clínico: Presentamos el caso de un camerunés Cameroon who was referred because of the presen- que refiere la presencia de un gusano en ambos ojos ce of a worm in both eyes, intermittently, over a de forma intermitente desde hace 5 años. El examen five-year period. Slit-lamp examination revealed a biomicroscópico reveló la existencia de un gusano creeping worm under the conjunctiva. Its surgical reptante subconjuntival. El análisis microbiológico removal enabled microbiologic confirmation of a tras su extracción quirúrgica confirmó que se trata- mature form of Loa-Loa. ba de una forma adulta de Loa-Loa. Discussion: Loiasis is a parasitic disease endemic Discusión: La loiasis es una enfermedad parasitaria in Africa. Because of the increase of African emi- endémica en África. El reconocimiento de la enfer- gration to Spain, the possibility of this condition medad tiene interés debido al incremento de la emi- must be considered in Spain (Arch Soc Esp Oftal- gración africana hacia España. mol 2007; 82: 55-58). Palabras clave: Loa-Loa, Loiasis, parasitosis ocular. Key words: Loa-Loa, Loiasis, ocular parasitosis.

INTRODUCTION CASE REPORT

Loiasis is a filariasis which, until now, has been A 24 year-old male from Cameroon, resident in limited to African countries. The increase of Spain for 6 years, who visits his country once a year, African emigration to other countries like Spain attended the urgency service referring a feeling of a entails increased possibilities for the disease to strange body in movement in his right eye. In addition, grow beyond the regions in which it is endemic. the patient referred the intermittent presence of a This short communication presents a case of ocular worm in both eyes since 5 years ago, sometimes visi- loiasis with direct identification of the worm which ble under the palpebral skin. For this reason he attend- allowed for confirmation of the disease. ed the general urgency service on several occasions.

Received: 1/6/05. Accepted: 20/12/06. Hospital Juan Canalejo. La Coruña. Spain 1 Graduate in Medicine. 2 Ph.D. in Medicine. 3 Graduate in Pharmacy.

Correspondence: I. López Rodríguez C/. San Ignacio, 1, 4.º C 15001 La Coruña Spain E-mail: [email protected] LÓPEZ-RODRÍGUEZ I, et al.

The anterior pole assessment revealed the exis- after 3 months, they reach the adult stage. The tence of a mobile cord-shaped structure which microfilariae couple under the skin, with females moved under the upper bulbar conjunctiva of the segregating microfilariae into the peripheral blood patient’s right eye (fig. 1). In accordance with this after 6-12 months of parasitation, during the day- finding, we proceeded to surgical extraction under light period with peak activity at noon (1). local anesthesia of a whole 5 cm long worm (fig. 2). After a 3-month incubation period typical The microbiological study confirmed the diag- expressions appear which are usually well tolerated, nostic of adult female Loa Loa worm. resulting from the subcutaneous migration of adult vermin and immunoallergic responses: — Pruritus: in upper limbs, chest, back and face. DISCUSSION — Subcutaneous reptation of adults: a disagree- able itching appears while an undulating chord Loiasis is a parasitic disease which is endemic in moves under the skin at a rate of 1 cm per minute. West and Central Africa (Nigeria, Cameroon, Con- Subconjunctival migration is pathognomic for Loa- go). It is estimated that the number of individuals Loa and produces the feeling of a foreign body, affected ranges between 3 and 13 million and that conjunctival injection, crying and palpebral/con- about 30% of long-term visitors become parasited junctival edema. by this organism. — Calabar edema: the most common albeit not Loa-Loa, also known as African eye worm, is a pathognomic sign, as it can appear in other filaria- thin-bodied filarial nematode of the human species. sis. This edema is characterized by its appearance in Males reach 2-4 cm length and 0.3-0.4 mm width limbs (wrists, ankles) or painful face, pruritus or and females 5-7 cm by 0.5 mm. urticaria followed a few hours later by a migrating, The biological vital cycle requires the participa- transient angioedema lasting between 1 and 3 days. tion of a vector arthropod, the female of the Late complications may appear involving the Chrysops species (deer fly). The fly bites a contam- kidneys (interstitial nephritis), heart (right cardiac inated human and ingests blood containing microfi- insufficiency) or neurological expressions (menino- lariae. In the fly, the microfilariae progress through goencephalitis), associated to hypersensitivity or to several stages to reach the infectious larvae stage patients with high microfilaremia (2). after 10-12 days. It is transmitted to humans Due to the increased amount of people traveling through the fly’s bite. From the skin, the larvae through highly endemic areas and to the increased migrate to the subcutaneous cellular tissue wherein, emigration of inhabitants of said areas to our coun- try, we believe awareness about this pathology and being alert to patients at risk will prevent the mor-

Fig. 2: Female Loa-Loa in adult form after subconjunc- Fig. 1: Subconjunctival Loa-Loa. tival extraction. 56 ARCH SOC ESP OFTALMOL 2007; 82: 55-58 Ocular loiasis bidity associated to ocular loiasis. Once recognized, Other drugs which are utilized are ivermectine, this disease has a simple and efficient treatment. with a single 150 ug/kg dosage for reducing the The diagnostic is mainly clinical, suspecting microfilaremia in cases where DEC may have patients who have been in the endemic area and adverse side effects, as well as mebendazole and exhibit symptoms suggesting loiasis (3) although in albendazole (5). cases such as the present one, the subcutaneous or As the human is the only known host for Loa-Loa subconjunctival migration add certainty to the diag- and the infection is transmitted by the deer fly, it is nostic with the identification of the worm after surgi- advisable to carry out chemical prophylaxis for cal removal. In most cases, the diagnostic is estab- people who live for some time in endemic regions, lished by microscopic observation of microfilariae in utilizing DEC orally at a single weekly 300 mg take vivo or after coloring hematic preparations, together (or one dosage of 5 mg/kg/day for 3 days every with an assessment of the supplementary analytical month), together with personal protection means finding (eosinophilia, PCR, quantified IgE). such as use of insecticides and repellants The surgical removal of the complete worm after (dimethylphtalate), the use of long trousers and pro- topical or subconjunctival anesthesia (sometimes tection during sleep. paralyzing the worm with 4% cocaine) is simple and effective. The literature describes cases in which the worm was paralyzed with cryode for sub- REFERENCES sequent extraction (4). The drug of choice is diethylcarbamazine (DEC), 1. Carbonez G, Van De Sompel W, Zeyen T. Subconjunctival Loa Loa worm: case report. Bull Soc Belge Ophtalmol efficient against the adult and microfiliar forms of 2002; 283: 45-48. the worm, to be administered in several cycles. This 2. Jolly BT, Foley KA. Loiasis: a case of an unusual ocular treatment is not free of undesirable effects such as foreign body. Ann Emerg Med 1992; 21: 1153-1156. worsening of symptoms and kidney or encephalic 3. Patel CK, Churchill D, Teimory M, Tabendeh H. Unex- complications, particularly in patients with high plained foreign body sensation: Thinking of loiasis in at risk patients prevents significant morbidity. Eye 1993; 7: microfilaremia. In these cases, treatment must 714-715. begin at low dosage to be progressively increased, 4. Geldelman D, Blumberg R, Sadun A. Ocular Loa Loa with and associating antihistaminic and corticoids the cryoprobe extraction of subconjuntival worm. Ophthalmo- first 4 days (treatment pattern with DEC: day 1: logy 1984; 91: 300-303. 5. Fobi G, Gardon J, Santiago M, Ngangue D, Gardon-Wen- 1 mg/kg in a single take; day 2: 2 mg/kg in two del N, Boussinesq M. Ocular findings after ivermectin tre- takes; day 3: 4 mg/kg in two takes; day 4-21: 6- atment of patients with high Loa-loa microfilaremia. 9 mg/kg in 3 takes). Ophthalmic Epidemiol 2000; 7: 27-39.

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