Rare presentation of rickettsial infection as purpura fulminans

Purpura fulminans (PF) is a term used to describe a heterogeneous group of disorders characterized by rapidly progressive purpuric lesions that develop into extensive areas of skin necrosis and peripheral gangrene [1]. Purpura fulminans is known to be associated with many infections, such as menin-gococcal, staphylococcal, and streptococcal infections. There are very few reports of this entity with spotted fever group rickettsioses and scrub typhus in Sri Lanka.

A 33-year-old female with intellectual disability since childhood presented with an acute febrile illness for seven days. She also had severe arthralgia, conjunctival suffusion, and a widespread "fern-leaf pattern" necrotic skin rash involving both upper limbs and lower limbs, sparing the face and trunk. She had a very high antibody titer against Rickettsia Conorii antigen, confirming the diagnosis of SFG rickettsioses, and recovered completely with anti-rickettsial therapy.

Clinicians should consider rickettsial infection as one of the differential diagnoses in a patient presenting with acute febrile illness with patchy necrotic skin lesions which would help in early diagnosis and initiating appropriate treatment, thus preventing a deleterious outcome.