Rickettsioses: Cutaneous findings frequently lead to diagnosis – a review

Abstract

While epidemic typhus caused by Rickettsia prowazekii posed a significant threat in Europe before and throughout World War II due to its high mortality, the condition fortunately no longer plays a significant role. Nevertheless, rickettsioses, such as African tick bite fever, have been increasingly diagnosed in travelers returning from sub-Saharan Africa. Caused by Rickettsia africae, African tick bite fever presents with characteristic cutaneous findings such as eschar (tache noir) and a rash. Similar findings are also observed in Mediterranean spotted fever caused by Rickettsia conorii. On the other hand, Rocky Mountain spotted fever – caused by Rickettsia rickettsii – is characterized by a rash without an eschar, in combination with distinctly more severe general symptoms. The objective of the present CME article is to familiarize dermatologists with the spectrum of the most common types of rickettsiosis in humans, including their epidemiology, clinical presentation, diagnostic workup, and treatment. Recognition of characteristic cutaneous manifestations and their correct interpretation facilitate early diagnosis. Prompt initiation of treatment usually results in recovery without sequelae.