A 20 year old woman died of respiratory failure due to cicatricial pemphigoid ofthe trachea and bronchi. This is the first case with the lower airways affected to be reported.Cicatricial pemphigoid, or benign mucus membrane pemphigoid,'2 is a chronic bullous disease primarily affecting mucus membranes and less frequently the skin. It occurs from the second to the eighth decade of life, but is more common in the elderly. Its course is usually benign, though conjunctival scarring may cause visual impairment. The respiratory tract is rarely affected, and in previously reported cases disease has been limited to the larynx.'-2 We present a patient who died of respiratory failure caused by lesions in the trachea and bronchi. Case reportA 20 year old Bolivian woman was admitted to our hospital from another centre with mucosal ulceration and respiratory dysfunction. She had been healthy until September 1986, when a painful blistering eruption had developed in the mouth and vulva, which partially resolved with prednisolone. One month later typhoid fever was diagnosed, and she was treated with chloramphenicol, sulphamethoxazole, and trimethoprin. A few days later there was an abrupt onset of a generalised cutaneous bullous rash, thought to be erythema multiforme, so antibiotics were discontinued. The rash resolved but the mucosal lesions persisted. A lip biopsy specimen taken at the time was reported as showing the histological changes of pemphigus vulgaris, though no immunofluorescence studies were carried out. Prednisolone (70 mg/day) was reintroduced, again with partial improvement, but it was withdrawn after three weeks, after the onset ofdepressive psychosis. At this time the patient also began to complain of dyspnoea, cough, and wheeze. The respiratory symptoms progressively worsened; bron- Accepted 28 February 1989 chodilators and steroids afforded some relief but again steroids had to be discontinued, and she was transferred to our care.On admission she was afebrile but distressed, dyspnoeic, and cachectic, with painful ulceration and scarring of the vulva and mouth and blistering of the face and trunk. The conjunctivae were ulcerated and scarred, and early synechiae were present. There was prolonged expiration and wheeze, and chest radiography and computed tomography showed hyperinflated lungs and distended bronchi (fig 1). Arterial oxygen tension was 7-3 kPa and arterial carbon dioxide tension 8 kPa; FVC was 1 08 (pred 3 64)1, FEV, 0-53 1 (pred 2-99 1), PEF 108 1/min (pred 379 1/min), and FEF 25-75% 0-23 (pred 3 68) 1/s. The airways obstruction was unaffected by inhaled salbutamol. Oesophageal and tracheal ulcers surrounded by cicatricial areas were seen at endoscopy.Laboratory investigations showed mild anaemia, a total white cell count of 4-8 x 109/1, and reactive bone marrow. Antinuclear factor, lupus erythematosus cells, rheumatoid factor, circulating immune complexes and anti-basement membrane antibody were absent; serum complement and immunoglobulin concentrations were within normal limits.Biop...