Tracheobronchitis and oesophagitis due to herpes simplex virus (HSV) are rare. Tracheo-oesophageal fistula due to HSV oesophagitis has been described in the immunocompromised host. A case is reported of a broncho-oesophageal fistula which developed secondary to herpetic bronchitis in an apparently immunocompetent patient. (Thorax 1995;50:906-907) Keywords: herpes simplex virus, bronchitis, bronchooesphageal fistula.Immunosuppressed, and occasionally immunocompetent, patients are susceptible to infection of the respiratory epithelium and the gastrointestinal epithelium with the herpes simplex virus (HSV). The endoscopic changes seen in association with HSV infection of the tracheobronchial tree and oesophagus are varied, ranging from normal to areas of ulceration with or without an inflammatory membrane. This membrane consists of fibrin and a purulent exudate. The inflammation can extend deeper and produce a fistula between the tracheobronchial tree and the oesophagus. Two cases of tracheo-oesophageal fistula in association with HSV oesophagitis in im- munocompromised patients have been described. 2 Here we describe such an occurrence in an elderly, apparently immunocompetent patient.Case report An 82 year old man presented with a 10 day history of cough, shortness of breath, dysphagia, and vomiting. In the past he had suffered from atrial fibrillation, pernicious anaemia, and glaucoma. Medications included digoxin, procainamide, aspirin, timoptic and phosphoiodine eyedrops, and monthly vitamin B.2 injections. He had a 60 pack-year history of cigarette smoking but had stopped at the age of 50. He did not drink alcohol.On examination the pulse was 84 and regular, the blood pressure was 1 10/60, respiratory rate 16, and temperature 37 5°C. Severe osteoarthritic changes were present in the knees. Visual acuity was poor and he was clinically dehydrated. Examination of the chest revealed diffuse rhonchi and wheezes. The cardiac, abdominal, and neurological examinations were normal. Stool was negative for occult blood.The WBC count was 7700/mm3, platelet count 406 000/mm3, and haemoglobin 11-3 g/ dl. The peripheral blood helper T cell (CD4) count was 812/mm3 and serum electrolyte levels were normal. Digoxin and procainamide levels were therapeutic. The serum urea concentration was 61 mg/dl and the creatinine concentration was 2-2 mg/dl; these became normal after hydration. Chest radiography showed bilateral lower lobe infiltrates; abdominal radiographs were unremarkable. An ECG showed sinus rhythm rate of 100 and ST changes consistent with a digoxin effect. Arterial blood gas tensions while breathing room air showed a pH of 7-40, Paco2 4-8 kPa, and Pao2 9-2 kPa. Sputum cultures grew Staphylococcus aureus and Pseudomonas aeruginosa.The patient was given antibiotics and intravenous fluids. All oral feedings were withheld. A barium swallow showed barium from the proximal oesophagus entering the left main bronchus, producing a bronchogram. Oesophagoscopy showed a fistula into the tracheobronchial tree at 30 cm w...