1
Introduction
Helminthic infestation in humans has been known to exist as long as the human race itself. Helminthic infestations producing cutaneous manifestations in human beings are of 3 varieties, namely, nematodes (worms), trematodes (flukes), and cestodes (tape worms). Cutaneous manifestations may occur during the varied stages of worm penetration, invasion, and development. Subcutaneous nodules and papules are features of underlying helminthic occupation and development, in the form of adult worms, eggs, or larvae.
Loa loa or the African eye worm is a filarial nematode endemic to Central and West Africa, Yemen, Saudi Arabia, and India. The microfilaria are transmitted to humans by the blood-sucking tabanid flies of the genus Chrysops (deer fly, horse fly, and mangrove fly) that bite by day . The adult worms migrate through subcutaneous tissue usually at the rate of about 1 cm/min and may not evoke any symptoms . However, when they remain in one spot for a short time, a fugitive swelling called the Calabar swelling may result, which may disappear with the movement of the worm. A subcutaneous live worm, calabar swellings, peripheral eosinophilia, and demonstrable microfilaria are said to be diagnostic of Loa loa infection .
Although Loa loa has been frequently reported from the eye and from different subcutaneous locations, it is rarely found over the nasal cavity. The case is reported here for the sheer rarity of finding an adult live worm on the bridge of the nose but without peripheral eosinophilia and demonstrable microfilaria. The report also highlights the unique radiological features associated with the infestation.
2
Case report
A 42-year-old lady who was a coir worker by occupation was referred to our outpatient department with the complaints of swelling over the dorsum of the nose since the past 2 months. The swelling had appeared insidiously and progressed gradually without any signs of sudden increase or decrease in size. The swelling was painless and showed no signs of infection or inflammation, nor was it secondary to any traumatic event. Her history was significant in that she had noticed a transient swelling on the left arm 4 months back that had come on acutely and lasted for 3 days. It was associated with symptoms of mild pain and disappeared without any active intervention. There were no other rhinologic complaints of note.
The examination of the patient revealed a moderately built and well-nourished lady with normal general physical and systemic examination result. The swelling on the dorsum of the nose appeared to be 2 × 1.5 cm, solitary, and in the midline extending from the nasion to the rhinion. The skin over the swelling was stretched and shiny and devoid of any scars, sinuses, fistulae, or punctum.
There was no cough impulse or visible pulsations. On palpation, however, the swelling was firm, nontender, subcutaneous in location, and mobile over the underlying bone. The result of the rest of the otorhinolaryngological examination appeared normal. A clinical differential diagnosis of dermoid, sebaceous cyst or inflammatory cutaneous swelling was made.
The patient was investigated with routine blood parameters in view of the operative intervention planned. An ultrasonographic examination before a fine needle aspiration of the mass was planned. Ultrasonographic examination surprisingly revealed mobile internal linear echogenicities in the subcutaneous plane of the nose, reported as live adult worms ( Fig. 1 ). An aspiration was not done for obvious reasons; however, a computed tomographic scan and nasal endoscopy were performed. There was no underlying bony defect or erosion into the nasal cavity. The result of a diagnostic nasal endoscopy was also normal. With a confirmed diagnosis of subcutaneous larval nodule, an absolute eosinophil count and a radiograph of the chest was performed, which were all within the normal limits. Result of a detailed ocular examination for parasites was negative, so also was blood samples sent for microfilariae.
