LAUSR

A 9yearold girl, on maintenance therapy for asthma, presented with 3 weeks of increasing dyspnoea. She had tachypnoea, hypoxaemia and bilateral crepitations on chest auscultation. Blood investigations revealed anaemia, leucocytosis and peripheral eosinophilia (table 1). Chest Xray showed bilateral midzone infiltrates (figure 1A). A chest highresolution CT (HRCT) scan performed after absence of clinical improvement with therapy, revealed bilateral central varicoid bronchiectasis, with tubular mucoid impaction in dilated bronchi in right lower lobe, called the ‘toothpaste sign’ (figure 2A). Within it is an area of higher attenuation (figure 2B), appearing denser than that of the paraspinal muscle, called the highattenuation mucus (HAM) sign. Subsequent blood investigations confirmed allergic bronchopulmonary aspergillosis (ABPA) (table 2). With oral corticosteroid therapy, there was consequent clinical, radiological and serological improvement (figure 1B). ABPA, an allergic fungal disease following type 1 hypersensitivity reaction to Aspergillus fumigatus antigens, commonly complicates asthma and cystic fibrosis. Patients present with difficult to treat asthma, recurrent pulmonary infiltrates, or bronchiectasis and its sequelae. Central bronchiectasis and HAM are the most characteristic associated radiological signs. The ‘toothpaste sign’ or ‘glovedfinger sign’ is reported in bronchiectasis complicating ABPA, cystic fibrosis, bronchial atresia or distal to any endobronchial obstruction. HAM sign, though pathognomonic, is not seen in all patients with ABPA and is attributed to high calcium and other metal salt content within. 3 Diagnosing ABPA