Occam's razor or Hickam's dictum? Allergic bronchopulmonary aspergillosis and eosinophilic granulomatosis with polyangiitis*

*Occam’s razor, named after William of Ockham a Franciscan friar of the early 14th century, refers to the principle of logic that states that the simplest explanation is the most likely correct; in science with competing hypotheses, the one with the fewest assumptions is preferred. Hickam’s dictum is the counter-argument to Occam’s razor in medicine; the statement ‘Patients can have as many diseases as they damn well please’ attributed to John Hickam, a great US physician and educator, who originally published research on lung function in heart and lung disease.