Various rickettsiae, transmitted by ticks, cause spotted fevers similar to Rocky Mountain spotted fever. They cause a small sore at the site of the tick bite, swelling in nearby lymph nodes, and a red rash.
Spotted fevers include North Asian tick-borne rickettsiosis, Queensland tick typhus, African tick typhus, and Mediterranean spotted fever (boutonneuse fever).
Like Rocky Mountain spotted fever, other spotted fevers may occur in the United States and internationally. These infections occur mainly in the spring and summer, when adult ticks are active and people are likely to be in tick-infested areas. In warmer climates, the disease may occur throughout the year. Mediterranean spotted fever can occur year-round in the Mediterranean region because it is transmitted by the brown dog tick and thus may be acquired indoors.
Symptoms of these infections are similar. About 5 to 7 days after a bite, a fever, fatigue, muscle aches, and headache develop. The eyes are red, and people feel generally unwell. A small buttonlike sore covered by a black scab (eschar) develops at the site of the bite. Usually, nearby lymph nodes are swollen. About 4 days after the fever starts, a red rash appears on the forearms and spreads to most of the body, including the palms and soles. Fever typically lasts over a week.
When appropriately treated, these infections rarely cause serious problems or death. Problems are more likely to occur in older people and people who already very ill.
Symptoms suggest the diagnosis (see Diagnosis), but to confirm it, doctors usually do an immunofluorescence assay and use the polymerase chain reaction (PCR) technique, which use a sample from the rash or blood. These techniques make the bacteria easier to detect and identify.
The antibiotic doxycycline or ciprofloxacin is usually given for 5 days.
To prevent these infections, people should take measures to prevent tick bites (see Fig. 2: Preventing Tick Bites).
Last full review/revision March 2013 by William A. Petri, Jr., MD, PhD