Other Spotted Fevers
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.
Rickettsiae are a type of bacteria that can live only inside the cells of other organisms (see also Overview of Rickettsial Infections).
Spotted fevers include the following:
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 spotted fevers 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.
Doctors may do blood tests that detect antibodies to the bacteria. However, these test cannot detect the antibodies until at least several days after the illness begins. Thus, these tests do not help doctors diagnose the infection immediately after someone becomes ill but can help confirm the diagnosis.
Doctors immediately prescribe an antibiotic, usually doxycycline, if they suspect a spotted fever based on symptoms and the potential for exposure to infected ticks—even if laboratory test results are not yet available. The antibiotic is given for 5 days.
To prevent these infections, people should take measures to prevent tick bites.