A rare case of spotted fever group rickettsiosis in southern Iran: diagnostic challenges and review.

BACKGROUND: Mediterranean spotted fever (MSF), caused by Rickettsia conorii and transmitted by the brown dog tick (Rhipicephalus sanguineus), is endemic in Mediterranean regions. In non-endemic countries such as Iran, spotted fever group (SFG) rickettsioses are rarely reported and present significant diagnostic challenges due to overlap with common illnesses like measles and dengue fever. CASE PRESENTATION: A 58-year-old man from Hormozgan Province, southern Iran, with diabetes and ischemic heart disease, presented with two weeks of high fever, chills, weakness, maculopapular rash, and severe myalgia. Initially misdiagnosed as measles and tested negative for dengue, further history revealed occupational contact with Tatera indica rodents. Examination revealed fever (39.5 °C), rash on the extremities and trunk, and a calf eschar. Key labs included elevated AST (118 U/L), ALT (106 U/L) and CRP (33.98 mg/L). Empirical doxycycline (100 mg twice daily) was started. IFA IgM was positive at a high titer (1:768), with a subsequent convalescent sample showing IgG seroconversion. Fever resolved within 48 h; he was discharged after five days with improving symptoms and labs. CONCLUSION: This case illustrates the diagnostic challenges of SFG rickettsioses, most consistent with probable MSF, in a non-endemic region of Iran. It potentially emphasises the value of detailed exposure history and prompt empirical doxycycline in suspected cases. Greater awareness, improved access to diagnostics, and enhanced surveillance are needed to better recognise these infections in Iran, especially in Hormozgan province.