Clinical disease Relapsing Fever is a disease characterized by relapsing (i.e. recurring) episodes of fever, often accompanied by other symptoms. Symptoms | Intial Symptoms | Other/Later symptoms |
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| fever | nausea | | generalized body aches | vomiting | | myalgias | anorexia | | arthalgias | dry cough | | headache | photophobia | | chills | rash | | sweats | neck pain | | | eye pain | | | confusion | | | dizziness |
From Dworkin, Anderson et al. 1998 Timing Incubation period = time from tick bite to illness 7 days, range 2 to 18 days Length of illness = time from symptom onset to resolution of symptoms 3 days, range 2 to 7 days Length of time before reoccurrence = time from resolution of symptoms to reoccurence of symptoms 7 days, range 4 to 14 days Number of relapses = number of episodes of reoccurring/relapsing symptoms 3 times, can occur up to 10 times in persons who are not treated. Crisis As fever is resolving, there is a classic series of stages that a person will go through, collectively known as a "crisis". 1. Phase one is the chill phase, with the person experiencing high fevers up to 41.5°C (106.7°F). With this high temperature, a person can develop delirium, agitation, and confusion. In addition, other signs of an increased metabolic rate are noted, such as a fast heart rate and breathing rate. This phase lasts between 10 and 30 minutes. 2. Phase two is the flush phase. This is where the body temperature decreases rapidly and the person has drenching sweats. During this phase, the person's blood pressure can drop dramatically. Physical Exam Although there can be multiple findings on physical exam there are no classic findings for TBRF. The most evident finding is a moderately ill appearing person who is mildly to moderately dehydrated. Some people develop mild to moderate hepatosplenomegaly, enlarged liver and spleen. Often there is accompanying yellowing of the skin or jaundice. Skin exam can reveal a nonspecific macular rash and/or scattered petechiae. Other potential findings on clinical exam include meningismus (stiff neck and headache with photophobia), pleuritic pain and rub (chest pain), conjunctivitis (red eyes), photophobia (fear of light), and sclarae icteric (yellowing of the white part of the eyes). TBRF in pregnancy TBRF contacted during pregnancy can cause spontaneous abortion, premature birth, and neonatal death (Melkert and Stel 1991). The maternal-fetal transmission of Borrelia is believed to occur either transplacentally (Steenbarger 1982) or while traversing the birth canal. In one study, perinatal infection with TBRF was shown to lead to lower birth weights, younger gestational age, and higher perinatal mortality (Jongen, van Roosmalen et al. 1997). In general, pregnant women have higher spirochete loads and more severe symptoms than nonpregnant women. Higher spirochete loads have not, however, been found to correlate with fetal outcome. Immunity Although there is limited information on the immunity of TBRF, there have been patients who developed the disease more than once. Differential Diagnosis The following infectious disease should be consider in someone with recurrent episodes of a febrile illness: | • Colorado tick fever | •Infectious mononucleosis | • Ascending (intermittent) cholangitis | | • Yellow fever | • African hemorrhagic fevers | • Lymphocytic choriomengitis | | • Dengue fever | • Leptospirosis | • Infections with echovirus 9 | | • Malaria | • Chronic meningococcemia | • Infections with Bartonella species | | • Brucellosis | • Rat bite fever | |
per Dworkin, Shoemaker et al. 2002 Morbidity and Mortality Given appropriate antibiotics, most patients feel better within a few days. Patients with TBRF, however, often report prolonged symptoms and time to recovery. Often this is due to delayed diagnosis and treatment. Long-term sequelae of TBRF include cardiac and renal disturbances, peripheral nerve involvement, ophthalmia, and abortion. With treatment the mortality is very low. The mortality without treatment is not known but it has been estimated at 5-10%. | 
