CUTANEOUS GNATHOSTOMIASIS in VIETNAM

CUTANEOUS GNATHOSTOMIASIS: A CASE REPORT IN VIETNAM

Le Dinh Vinh Phuc,  Lu Hoang Vu, Nguyen Trung Ngon

Medic Medical Center, Ho Chi Minh City, Vietnam 

Abstract. A 33 year-old tourist guide man living in Ho Chi Minh City, Vietnam came to Medic Medical Center in Ho Chi Minh City with  swellings at two forearms for 10 days. Lesions were gradually moving downward and sometimes he got feeling like something crawling under the skin with itching, pain, and redness. We suspected larvae migrans syndrome and appointed a number of tests. The eosinophil increased and the serology was positive for Gnathostoma IgG. We performed a skin biopsy from his right forearm lesion and caught a larva of Gnathostoma spinigerum. He was treated with a single dose of  ivermectin (200 μg/kg/day).  Re-examination after 3 weeks, clinical symptoms resolved very well and eosinophil returned to normal.

Correspondence: Le Dinh Vinh Phuc, Medic Medical Center, 254 Hoa Hao Street, Ward 4, District 10, Ho Chi Minh City, Vietnam.

Tel: 84.8.39270284 ; Fax: 39272543

Email: bsvinhphuc1981@gmail.com

INTRODUCTION

Gnathostomiasis is a parasitic infection caused by the third-stage larvae of the helminths Gnathostoma spp., which are seen mostly in tropical and subtropical regions [1].

In Vietnam, G. spinigerum, G. hispidum, G. doloresi, and G. vietnamicum have been documented in the literature [2]. However, only G. spinigerum is known to be responsible for human cases [3]. The first human case was due to G. spinigerum, described in 1965, in a boy from Tay Ninh province, with a migrating tumor on his head [2]. More than 20 years later, no more human cases have been reported. Until 1998, 3 human cases due to G. spinigerum were documented, with worms found in skin lesions [4].

The clinical features can be divided into immediate symptoms, a cutaneous form, and a visceral form. The triad of eosinophilia, migratory lesions, and obvious exposure risk are highly suggestive of the diagnosis of gnathostomiasis. Exposure risk must include residence in or travel to an area of endemicity and consumption of food that potentially contains the larval form of the parasite (raw or undercooked fish [in particular swamp eels, catfish, sleeper perch, bream, Nile tilapia, butterfish, loaches, or snake-headed fish], frogs, chickens, cats, or dogs) [1].

We report a case of cutaneous gnathostomiasis diagnosed by creeping eruption in both 2 arms and a caught larva from cutaneous lesion of the forearm.

CASE REPORT

On June 26, 2012, a 33 year-old man came to Medic Medical Center in Ho Chi Minh City with  swellings at two forearms. He is a tourist guide in a domestic company. He was healthy without a significant medical history. About 10 days now, he emerged swollen lesions from the skin and prominent zigzag in one third of the forearm between the two sides together with itching, pain, redness, and hot to the touch. Lesions gradually moving downward and sometimes he got feeling like something crawling under the skin (Figure 1).

Figure 1. Larvae migrate under the skin on the right and left forearms.

During physical examination and exploitation epidemiological factors we noted he occasionally eat frogs grill in restaurant. We think about illness larvae migrate to the skin and do some tests.

The red blood cell counts of 5,060,000/mm³ and a white blood cell counts of 8,830/mm³ (50.7% neutrophil, 35.3% lymphocyte, and 10.7% eosinophil, absolute eosinophil count = 940/mm³). The serology was positive for Gnathostoma IgG. He was sent to the operating room for a small incision of his forearm to catch the larva to identify. In the specimen we found out a larva of Gnathostoma spinigerum (Figure 2).

Figure 2. Specimen of  head of third-stage larvae of Gnathostoma spinigerum with four rows of spines.

DISCUSSION

Cutaneous gnathostomiasis is the most common manifestation of infection. It typically presents with intermittent migratory swellings, (nodular migratory panniculitis), usually affecting the trunk or upper limbs. These nonpitting edematous swellings vary in size and may be pruritic, painful, or erythematous [1]. The criteria for a diagnosis of cutaneous gnathostomiasis were based on 1) presence of migratory swelling lasting at least two days; 2) absolute eosinophil counts >500/mm³; 3) stool examination results negative for other parasites; 4) presence of antibodies against a specific 24-kD antigen for Gnathostoma spinigerum by Western blot analysis; 5) a history of eating raw freshwater fish, crab, snake, bird, or chicken; and 6) a positive skin test result for G. spinigerum. A person was diagnosed with cutaneous gnathostomiasis if he or she satisfied criteria 1, 2, 3, and 4, plus criteria 5 or 6 [5].

Our case includes typical clinical symptoms, epidemiological factor, eosinophil  increasing, positive serology and a caught larva from skin lesion.

Detection of the worm in the skin, although rarely found, is important to confirm the diagnosis of cutaneous gnathostomiasis. During 1986-1990, 127 patients were diagnosed with cutaneous gnathostomiasis but only 17 patients (13.39%) were found to have cutaneous worms (Kraivichian P, Yingyaud P, unpublished data). Thus, in most cases, only a presumptive diagnosis is made based on the clinical ground alone when the worm cannot be identified. Surgical removal of the worm is considered the best treatment for cutaneous gnathostomiasis. However, it is rather difficult to obtain the parasite [5].

In Vietnam, more than 600 cases from different cities of south Vietnam have been diagnosed based on clinical symptoms and signs, eosinophilia and ELISA at the Department of Parasitology, School of Medicine, University of Pharmacy and Medicine. Cutaneous gnathostomiasis accounted for 63.8%. In 10 parasitologically confirmed cases, larvae were found from the skin: 7 with spontaneously exiting larvae, 3 by skin biopsy. All 10 causative agents found were G. spinigerum [6].

We think finding the third-stage larvae to identify will be difficult because of its very small size compared to the lesions under the skin where it causes, and  depend on the experience of the surgeon.

REFERENCES

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2.         Hoa LV, Ai NV, Luyen TV, Gnathostoma and gnathosthomose humaine au Vietnam. Bull Soc Pathol Exot, 1965; 58:: p. 236-44.

3.         Xuan LT, Rojekittikhun W., A survey of infective larvae of Gnathostoma in eels sold in Ho Chi Minh City. Southeast Asian J Trop Med Public Health, 2000;31:: p. 133-7.

4.         Mai TX, Parasitic impass due to intestinal parasites of dogs and cats. Ho Chi Minh City: University of Medicine, 1992.

5.         Kanyarat Kraivichian, Surang Nuchprayoon, Prasert Sitichalernchai, Wanpen Chaicumpa and Sutin Yentakam , Treatment of cutaneous gnathostomiasis with ivermectin.. Am J Trop Med Hyg., 2004; 71 (5):: p. 623-8.

6.         Xuan LT, Hoa PTL , Dekumyoy P, Van TTH, Mai VTC , Hoan NH, Khuong LH, Tu LX, Hien TV. , Gnathostoma infection in south Vietnam. Southeast Asian Journal of Tropical Medicine and Public Health, 2004; 35:: p. 97-9.