Cough and dyspnoea of an asthmatic patient at Mt. Kilimanjaro: a difficult differential diagnosis.

This case highlights the difficulties associated with the differential diagnosis of pulmonary symptoms in patients with pre-existing diseases in extreme environmental conditions. A 58-year-old man with child-onset allergic asthma developed dyspnoea and an acute non-productive cough during a trekking expedition on Mt. Kilimanjaro (5895m) in Tanzania. The symptoms were believed initially to be linked to the high altitude exposure (high altitude pulmonary oedema (HAPE) or high altitude cough) or his pre-existing asthma. However, he was later diagnosed correctly with a reinfection of Bordetella pertussis. Pertussis is a highly communicable disease with potentially serious medical consequences that could have affected all of the expedition members. The effectiveness of a pertussis vaccine declines 4-12 years after the vaccination. Thus, it is suggested that the status of immunisation against pertussis should be checked along with those of other infections prior to travel.