Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
  Users Online: 291 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size  

 Table of Contents  
Year : 2013  |  Volume : 3  |  Issue : 1  |  Page : 64-65  

Subcutaneous nodule: A case of Dirofilaria

1 Department of Surgery, Father Muller Medical College, Mangalore, Karnataka, India
2 Department of Microbiology, M.E.S. Medical College, Perinthalmanna, Malappuram District, Kerala, India

Date of Submission01-Aug-2012
Date of Acceptance12-Mar-2013
Date of Web Publication18-May-2013

Correspondence Address:
Reshmina D'Souza
Department of Surgery, Fr. Muller Medical College, Mangalore - 575 006, Dakshina Kannada District, Karnataka
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2229-516X.112243

Rights and Permissions

Human subcutaneous dirofilariasis is a rare helminthic infection. It is caused by filarial worms of the Genus Dirofilaria, which is the natural parasites of dogs, cats, foxes, and wild mammals. Zoonotic filariasis caused by Dirofilaria species is rarely seen in the region of Dakshina Kannada. Most of them are seen in patients who are along the border of the district which shares its boundary with the state of Kerala, where dirofilariasis is constantly reported to occur. Here, we report a case of subcutaneous dirofilariasis, presenting as a subcutaneous nodule on the left cheek of a 28-year-old male from Cochin (Ernakulam), Kerala, South India. Two live worms were recovered from the subcutaneous nodular swelling.

Keywords: Dirofilariasis, subcutaneous nodule, zoonotic filariasis

How to cite this article:
D'Souza R, Jakribettu RP, Sudharsana H S, Aithala P S. Subcutaneous nodule: A case of Dirofilaria. Int J App Basic Med Res 2013;3:64-5

How to cite this URL:
D'Souza R, Jakribettu RP, Sudharsana H S, Aithala P S. Subcutaneous nodule: A case of Dirofilaria. Int J App Basic Med Res [serial online] 2013 [cited 2021 Aug 4];3:64-5. Available from: https://www.ijabmr.org/text.asp?2013/3/1/64/112243

   Introduction Top

Human subcutaneous dirofilariasis is a rare helminthic infection. It is caused by filarial worms of the genus Dirofilaria species, which is the natural parasites of dogs, cats, foxes, and wild mammals. [1] Dirofilaria species belongs to the filarial nematodes, causes zoonotic infections in man, occasionally. Subcutaneous dirofilariasis is caused mainly by Dirofilaria repens, which causes subcutaneous nodules in and around the eye. It is a common parasite of dog, seen mainly in the subcutaneous tissue. The mosquitoes Culex, Aedes, and even Anopheles species form the vector for this nematode.

   Case Report Top

A 28-year-old male hailing from Cochin, South India presented with a subcutaneous nodule on the left cheek of duration of 2 weeks, which was gradually increasing. On clinical examination, he had a firm oval swelling on the left cheek measuring 1.5 cm × 1 cm, which was non-tender and freely mobile. The systemic examination was unremarkable. A clinical diagnosis of a subcutaneous swelling/Sebaceous cyst was made, and the swelling was excised as an out-patient procedure under local anaesthesia. On excision two live thread like cylindrical worms, 0.5 mm thick measuring about 10-25 cm were found, coiled to each other. On macroscopic examination, of both the worms it was found that both the worms had a short and rounded tail [Figure 1]. No lips were seen in the mouth. Under the microscope, the outer surface of the nematode's cuticle was found to have fine transverse striations and prominent longitudinal ridges [Figure 2]. Shorter worm had unequal caudal spicules hence identified as male dirofilarial worm. The longer worm had oesophagus anterior to the vulva and was identified female dirofilarial worms. On the basis of macroscopic and, microscopic examination, worm was thus identified as D. repens.
Figure 1: Two live dirofilarial worms

Click here to view
Figure 2: Microscopic picture of the worm showing Cuticle and transverse striation

Click here to view

The hemogram showed hemoglobin 13 g%, total leucocyte count 10,200/mm 3 and differential count showed eosinophilia, with absolute eosinophil count 2060/mm 3 . The peripheral smear showed relative eosinophilia without any parasite. No microfilaria were seen in peripheral blood. The patient did not review after the excision of the nodular swelling for follow-up.

   Discussion Top

Human subcutaneous dirofilariasis is a rare helminthic infection, caused by filarial worms Dirofilaria species. It is an occasional zoonosis disease. The worm is a natural parasites of dogs, cats, foxes, and wild mammals. [1] Dirofilaria parasites are transmitted to man by mosquitoes. Most of the dirofilariasis cases are asymptomatic. The symptomatic ones typically manifests as either subcutaneous nodules or lung parenchymal disease. Excision of the subcutaneous lesion is both diagnostic and therapeutic. The clinical implication of human dirofilariasis is that, these subcutaneous lesions may be initially misidentified as malignant tumors, requiring invasive investigation and surgery before the correct diagnosis is made. The pathology of the condition results from the aberrant localization of immature worms intended for nonhuman hosts. Among the documented cases of human dirofilariasis in India, most of them had ocular infections. [2],[3],[4] In India and the Asian subcontinent D. repens is the main causative agent of subcutaneous human dirofilariasis. [5],[6] The Coastal Kerala is endemic for dirofilariasis due to the presence of the suitable vector and climatic condition. [1] Most of the cases of Dirofilariasis reported from the northern [3] and western parts [7] of India is caused by D. repens. Few cases of Dirofilaria immitis have been also reported from India. [6],[7]

The cause of endemicity in Southern-India and Sri Lanka is mainly due to drastic changes in climatic conditions especially humidity and rainfall pattern, which favor the development of vector mosquitoes and the larval phase of the nematode in the mosquitoes. Recently two more cases have been reported from the Southern-India presenting as subcutaneous nodules. [8] Most cases are diagnosed retrospectively, when the histopathological sections of biopsy or excision material are viewed. [5],[6] As microfilaremia is rarely seen in dirofilariasis chemotherapy is not called for. [5],[6] Thus, this case emphasizes that Subcutaneous Dirofilariasis should be considered as the differential diagnosis in case of a single subcutaneous swelling, especially, when the patient is coming from an endemic area.

   Acknowledgment Top

We would like to acknowledge Dr. B. Sanjeev Rai, Chief of Medical Services, Fr. Muller Charitable Institutions and Fr. Denis D'Sa, Administrator, Fr. Muller Medical College, Mangalore for their constant support for our research projects.

   References Top

1.Sabu L, Devada K, Subramanian H. Dirofilariosis in dogs and humans in Kerala. Indian J Med Res 2005;121:691-3.  Back to cited text no. 1
2.Nadgir S, Tallur SS, Mangoli V, Halesh LH, Krishna BV. Subconjunctival dirofilariasis in India. Southeast Asian J Trop Med Public Health 2001;32:244-6.  Back to cited text no. 2
3.Gautam V, Rustagi IM, Singh S, Arora DR. Subconjunctival infection with Dirofilaria repens. Jpn J Infect Dis 2002;55:47-8.  Back to cited text no. 3
4.Sekhar HS, Srinivasa H, Batru RR, Mathai E, Shariff S, Macaden RS. Human ocular dirofilariasis in Kerala Southern India. Indian J Pathol Microbiol 2000;43:77-9.  Back to cited text no. 4
[PUBMED]  Medknow Journal  
5.Padmaja P, Kanagalakshmi, Samuel R, Kuruvilla PJ, Mathai E. Subcutaneous dirofilariasis in southern India: A case report. Ann Trop Med Parasitol 2005;99:437-40.  Back to cited text no. 5
6.Singh R, Shwetha JV, Samantaray JC, Bando G. Dirofilariasis: A rare case report. Indian J Med Microbiol 2010;28:75-7.  Back to cited text no. 6
[PUBMED]  Medknow Journal  
7.Badhe BP, Sane SY. Human pulmonary dirofilariasis in India: A case report. J Trop Med Hyg 1989;92:425-6.  Back to cited text no. 7
8.Permi HS, Veena S, Prasad HK, Kumar YS, Mohan R, Shetty KJ. Subcutaneous human dirofilariasis due to dirofilaria repens: Report of two cases. J Glob Infect Dis 2011;3:199-201.  Back to cited text no. 8


  [Figure 1], [Figure 2]

This article has been cited by
1 Systematic Review of Lesser Known Parasitoses: Maxillofacial Dirofilariasis
Kirti Chaudhry,Shruti Khatana,Naveen Dutt,Yogesh Mittal,Yogesh Shailja Sharma,Poonam Elhence
Journal of Maxillofacial and Oral Surgery. 2018;
[Pubmed] | [DOI]
2 Subcutaneous Dirofilariasis of the Eyelid in a 7-Month-Old Infant
Vijaya H. Pai,Pallak Kusumgar,Kanthilatha Pai
Journal of Pediatric Ophthalmology & Strabismus. 2015; 52(6)
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
   Case Report
    Article Figures

 Article Access Statistics
    PDF Downloaded147    
    Comments [Add]    
    Cited by others 2    

Recommend this journal