Fig. 1

A 33-year-old female with hereditary angioedema (HAE). Soft tissue swelling of the neck during recurrent angioedema attacks. a The patient complained of neck swelling. Lateral radiograph of the neck shows thickening of the retropharyngeal soft tissue (asterisk), enlargement of the epiglottis with narrowing of the vallecula (large arrow), and thickening of the aryepiglottic folds (small arrow). b Six months later, the patient again complained of neck swelling and swallowing difficulty. Lateral view of the neck plain film shows enlargement of the epiglottis (large arrow, thumb sign) and thickening of the aryepiglottic fold (small arrow). No retropharyngeal soft tissue thickening is noted