Indian Journal of Dermatology
: 2015  |  Volume : 60  |  Issue : 4  |  Page : 420-

Subcutaneous infraorbital dirofilariasis

Anil S Krishna1, N Bilahari2, Savithry3, Robert P Ambooken4,  
1 Consultant in Oral and Maxillofacial Surgery, Daya Hospital, Thrissur, Kerala, India
2 Department of Oral Medicine and Radiology, PSM College of Dental Sciences and Research, Akkikavu, Thrissur, Kerala, India
3 General Pathologist, Polyclinic Pvt Ltd, Thrissur, Kerala, India
4 Department of Radiodiagnosis, Amala Institute of Medical Sciences, Thrissur, Kerala, India

Correspondence Address:
Dr. N Bilahari
Department of Oral Medicine and Radiology, PSM College of Dental Sciences and Research, Akkikavu, Thrisshur, Kerala


Dirofilariasis is a parasitic infection transmitted by mosquitoes from domestic and wild animals. Humans accidentally get infected and can present with a lung nodule, subcutaneous mass or an ocular lesion which will be either subconjunctival or periorbital. Proper microbiological and histopathological examinations aid in proper diagnosis. Herein, we present a case report of a 64-year-old female patient from Kerala with an infraorbital mass diagnosed as dirofilariasis.

How to cite this article:
Krishna AS, Bilahari N, Savithry, Ambooken RP. Subcutaneous infraorbital dirofilariasis.Indian J Dermatol 2015;60:420-420

How to cite this URL:
Krishna AS, Bilahari N, Savithry, Ambooken RP. Subcutaneous infraorbital dirofilariasis. Indian J Dermatol [serial online] 2015 [cited 2023 Sep 23 ];60:420-420
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Dirofilaria is a species that are natural parasites of dogs, cats, and wild mammals. The genus Dirofilaria consists of D. immitis, D. repens and D. tenuis. Pulmonary lesions can form from D. immitis, whereas D. repens and D. Tenuis cause ocular lesions. [1] Zooanthrophilic mosquitoes like culex, aedes, and anopheles have been regarded as vectors for dirofilariasis. [1],[2] Microfilariae get transmitted from the blood of wild and domestic animals such as the dog and cat to humans by infected mosquito bites. Humans are terminal host and the parasite will not produce any microfilariae in humans. [1] Human infection with Dirofilaria repens is comparatively rare in India; however, several cases have been reported in last few years, [1],[2] hence a proper knowledge of clinical pathological and microbiological features will help in prompt diagnosis and a proper management can be procured by the patient. We report a case of a 64-year-old female with subcutaneous dirofilariasis in the infraorbital region from Kerala, South India.

 Case Report

A 64-year-old female patient reported with a swelling on the left side of the face. Swelling was noticed 6 months back and over the past week there had been a mild reduction in the size of the swelling. The swelling was totally asymptomatic. Medical history revealed that patient is on medication for hypertension and asthma. However, she was not on steroid inhaler for treatment of asthma. Considering the zoonotic infections, she was asked about any contact with domestic animals or pets and the presence of mosquitoes in the area where she lived. However, she was not keeping any pets, but was living in a mosquito infested area. Hematological examination revealed no abnormalities and chest x-ray was normal in appearance.

On examination, a bony hard swelling was noticed on left infraorbital region measuring 3 × 2 cm in dimension and was non-tender on palpation. Aspiration was negative [Figure 1]a].{Figure 1}

Both ultrasonography (USG) and computed tomography (CT) scan suggested a parasitic infection with granuloma formation in facial muscle over left maxilla with diffuse edema of adjacent soft tissues [Figure 1]b and c].

Surgical excision of nodular mass was done and histopathological report was obtained [Figure 2]a]. Multiple sections of fibrofatty tissue with dense inflammatory cells and foreign body giant cells were noted. Cut section of filarial worm with thick laminated cuticle was also noted [Figure 2]b]. Hence a diagnosis of dirofilarial nodule was given. However, we failed to attain a full worm as most of the dead worm got necrosed. Healing was satisfactory and no recurrence was noted.{Figure 2}


Dirofilaria is a parasitic disease transmitted by mosquitoes, fleas and ticks. Dirofilaria can occur any where in the body. D. repens, D. immitis, D. tenuis, and D. ursi are some of the species commonly involved in human infections. [1],[2] Dirofilariasis has been reported from European countries especially Italy. [1] There has also been reports of dirofilariasis from other countries like France, Greece and Israel. [1] In India, subcutaneous Dirofilariasis is rare, only few cases having been reported. Ocular Dirofilariasis is a form of subcutaneous Dirofilariasis caused by D. repens. D. repens is a natural parasite of carnivorous animals, primarily dogs, foxes and cats. [2],[3] In USA, D. tenuis has been found in raccoons. [2] Many authors consider that D. repens is synonymous with D. conjunctivae and D. tenuis. [3] The percentage of parasitemia from D. repens in dogs varies from 12 to 37%.

Zoonotic filariasis occurs among those who are frequently in contact with cats and dogs. Subcutaneous dirofilariasis normally affects the eyelids and periorbital region and rarely can occur subconjunctivally also. [2]

The most common symptoms found in dirofilariasis are localized pruritis, pain, and swelling. Edematous, hyperemiac conjunctiva, with a sensation of movement under the skin or conjunctiva has also been reported. Allergic reactions with fever, urticaria, and facial edema are reported as other symptoms. [4] In a majority of instances parasites are found in excised nodule and biopsy specimens. D. repens has got a long thin filariform appearance. All dirofilaria have fine transverse striations on the cuticle and abundant somatic musculature. D. immitis lack prominent external longitudinal ridges. Longitudinal ridges of D. repens are broader with less distinctly raised and it appears branched. They have rounded anterior end. The diagnosis is usually established with the surgical removal of the adult worm. Microfilarias have never been reported in humans. In this case also repeated blood smears were negative for microfilaria and no eosinophilia reported. [2]

The diagnosis is confirmed by studying the morphology after their removal. Worms belonging to the genus. Dirofilaria are identified by their thick laminated cuticle, broad lateral ends and large muscle cells. The length of female may vary from 8 to 13 cm and males from 4 to 4.8 cm. [2] Though the worms with external longitudinal cuticular ridges [1],[3] are taken as D. repens there are other Dirofilaria, which may show these ridges. Exact identification of species may be possible only after studying the fully matured worm. [5] However, D. immitis can be differentiated from D. repens by absence of ridge in D. Immitis. [5] In our case also histopathological examination revealed a thick cuticle in the cut section of worm.

Surgical removal of the worm is the definitive choice of treatment. [6] In our case also surgically removal of the mass along with necrosed worm was done. Prognosis is good in case of Dirofilariasis.


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