Case of a subcutaneous nodule

Human dirofilariasis is an emerging zoonotic disease caused mainly by Dirofilaria repens and Dirofilaria immitis. Human dirofilariasis presents commonly as subcutaneous nodules, pulmonary nodules or nodules in the eye. We present a case of human dirofilariasis from India, presenting as a subcutaneous nodule on the scalp. Physical examination showed a well defined, tender and oval shaped nodule about 2 cm×2 cm on the left temporal region. The nodule was excised. Pathological examination revealed a nematode embedded in eosinophil rich granulomatous inflammatory infiltrate. Under the microscope, the nematode was identified as Dirofilaria repens based on morphology.