This can easily be mistaken for common viral illness. The rash in RMSF results from dissemination of the organism through the skin. It typically develops first on the wrists, hands, ankles and feet, spreading rapidly centrally to cover most of the body, including palms, soles and face. As the organism spreads through the circulation it causes bleeding of microscopic vessels leading to collapse of the vascular system and death. Neurologic involvement in RMSF ranges from mild headache to serious focal or generalized disorders of cerebral function.
Many patients report the worst headache of their lives.
Seizures may develop during the acute phase of the illness but rarely persist. Lethargy and confusion are common and may progress to stupor or coma. Death usually occurs between days 8 and 15 of illness. Diagnosis of RMSF must be made on the basis of clinical presentation and history in order to ensure timely therapy. The course of RMSF is one of advancing severity.