1

Introduction

Nicorandil is a Potassium channel activator with a Nitrate constituent. It causes vasodilation of arteries and veins leading to a decrease in preload and afterload. Mainly it is used in the management of angina. Otitis Externa (OE) is an inflammatory process of the external auditory canal and outer ear. The most common pathogen is Pseudomonas Aeruginosa. Malignant Otitis Externa (MOE) is a severe complication of OE where the infection extends to the underlying bone for example the temporal bone. Nicorandil use has been associated with ulceration at the muco-cutaneous interface zones. The first account of Nicorandil induced ulceration was reported in France in 1997 _. Numerous cases have been reported since, but to the best of our knowledge this is the first report of an ulcer affecting the external ear caused by Nicorandil. The diagnosis in our case proved challenging as Malignant OE was strongly suspected clinically.

2

Case history

A 70-year-old man was referred to the ENT department with a three-week history of unresolved OE. On examination there were a green–grey discharge from his left ear, a crusted weeping pinna and external ear canal, areas of skin and tissue breakdown anterior to the tragus with a one centimetre indurated ulcer with ( Fig. 1 ), sinus formation on the posterior aspect of the ear ( Figs. 1 and 2 ). Extensive Perianal ulceration with sinus formation was also noted.

Anterior view of the patient’s left ear showing skin and tissue breakdown at the anterior Tragus and 1 cm raised, pearly, non indurated ulcer underneath.

Posterior view of the left ear showing sinus formation.

He has a 20-year medical history of cardiovascular disease including two Myocardial Infarctions and a CABG. His medications included Amlodipine, Aspirin, atenolol, Lansoprazole, Isosorbide Mononitrate, Nicorandil 20 mg twice daily, Ramipril and Simvastatin. He was on oral Co-amoxiclav, topical bactroban ointment and sofradex ear drops for OE.

There was a high suspicion of malignancy so biopsies and swabs were taken of the ulcer and Auto-antibodies were tested to rule out a Vasculitis that could cause ulceration and the result was negative. A General surgical opinion was also arranged to determine the cause and management of the perianal ulcers. The results, found from the biopsies of the ear ulcer returned negative for malignancy, the swabs suggested a Group F streptococcal infection that was sensitive to Penicillin. The ENT team noted that there was no improvement of the OE and at this point the patient was admitted and Benzyl penicillin, Metronidazole and Ciprofloxacin were commenced. The differential diagnosis of Malignant OE or Malignancy was suggested and a CT of the temporal bone, Examination under anaesthetic (EUA) and more biopsies (to further exclude malignancy) were arranged. These biopsies were also negative for malignancy.

EUA revealed extensive soft tissue necrosis including necrotic skin in the posterior and anterior external auditory canal. As well as this there was a bony defect in the inferior canal. The CT of the temporal bone revealed a small bony breech in the floor of the medial aspect of the external auditory canal ( Figs. 3 and 4 ).

Coronal view CT scan of the Temporal bone shows a small bony breech in the floor of the medial aspect of the external auditory canal.

Transverse view CT scan of the temporal bone.

The General Surgeon suggested that perianal ulcers and sinuses might be induced by Nicorandil. It was suggested that under the supervision of the cardiologist Nicorandil should be stopped, and so it was discontinued.

The ulcer on his ear was followed up at one month and had shown considerable improvement after stopping the Nicorandil. The perianal ulcers had also shown considerable improvement at a 4-month follow up.