This case strikingly demonstrates how skin folds can mimic pneumothorax on AP chest radiographs, particularly in older patients. This issue tends not to occur with PA chest radiographs as in that case the patient's back is not pressed against anything and the hugging of the detector plate by the patient helps to stretch out any lax skin.

It is worth being aware of this potential pneumothorax mimic and noting that instead of the edge being a thin white line, a skin fold is always seen as a thick white line that fades in on one side and abruptly stops on the other side. Also, one can usually see vascular markings extending beyond the edge of a skin fold, whereas vessels would be completely absent in pneumothorax. Clinical assessment (auscultation and percussion) and ultrasound (to look for sliding lung sign) can be very useful to prevent a chest tube being needlessly inserted in cases such as this.