REVIEWDiagnosis and Treatment of Lyme Disease
Section snippets
EPIDEMIOLOGY AND RISK FACTORS
Lyme disease is the most common tick-borne disease in the United States.2, 3, 4, 5 It has been reported in all 50 states1 and is also found in Europe and Asia.6 Lyme disease is most commonly reported in New England and the mid-Atlantic states, upper north-central regions, and several counties in northwestern California. Variation in zoonotic factors, including the presence of the white-footed mouse and white-tailed deer, which are important hosts in the life cycle of the Ixodes tick, account
ETIOLOGY AND VECTOR LIFE CYCLE
The white-footed mouse is the primary animal reservoir for Lyme disease in the United States. Black-legged ticks (I scapularis, deer ticks) are responsible for transmitting Lyme disease bacteria (B burgdorferi) to humans in the New England and Great Lakes areas. In the West, B burgdorferi is transmitted to humans by the western blacklegged tick (Ixodes pacificus), although the incidence of the bacteria in these ticks is much lower.
The nymphal and larval forms of the Ixodes tick feed primarily
Early Localized Infection
Lyme disease presents in most cases with a characteristic lesion resembling a bull's-eye or target, known as erythema migrans. The rash appears as a homogeneous, erythematous, annular lesion that may exhibit partial central clearing late in the clinical course of the disease (Figure 4). In Europe, cases tend to have more prominent central clearing. According to CDC guidelines, the diameter of the lesion must be at least 5 cm (average size, 15 cm) to qualify as erythema migrans, but smaller
DIAGNOSIS
The diagnosis of Lyme disease is based on clinical features in a person who has traveled to or lives in an endemic area. In most cases, it is appropriate to treat patients who have early disease and a high pretest probability, on the basis of signs and symptoms, after a tick bite by the Ixodes species. As with other tick-borne diseases, only 50% to 70% of patients recall a tick bite,16 often because the deer tick nymphs are small and go unnoticed.
Common laboratory tests usually are not
TREATMENT
According to guidelines from the Infectious Diseases Society of America,2 recommended antibiotic treatment for Lyme disease includes doxycycline for nonpregnant patients aged 9 years and older (100 mg orally, twice daily) or amoxicillin for patients younger than 9 years (50 mg/kg per day orally), which are generally effective in early disease. Second-choice treatment for adults is amoxicillin (500 mg orally, 3 times daily). Cefuroxime axetil (500 mg orally, twice daily; or 30 mg/kg per day
ANTIBIOTIC PROPHYLAXIS
In many areas of the United States, tick bites are extremely common. B burgdorferi is endemic in New England, the mid-Atlantic states, Minnesota, and Wisconsin. In these areas, the risk of infection after a prolonged bite can be high (10%-25%).23, 24 Risk of infection is much lower in the southern and western United States. Furthermore, there is no risk of transmission of B burgdorferi from an unengorged tick because the spirochetes require up to 36 hours after a bite to migrate from the tick
LATE LYME DISEASE
Some manifestations of Lyme disease arise or persist even after a 2-week course of oral antibiotic therapy. For example, a few patients treated with oral agents have subsequently manifested neuroborreliosis, which may require intravenous therapy.29 Furthermore, up to 10% of patients have persistent or recurrent joint swelling after treatment.2 Although this swelling eventually resolves, it can last for several months after treatment. Patients whose joint swelling persists after a second 4-week
POST-LYME DISEASE SYNDROME
No accepted definition or diagnostic criteria exist for post-Lyme disease syndrome, also called chronic Lyme disease and posttreatment chronic Lyme disease. The term is applied to people with otherwise-unexplained subjective symptoms lasting more than 6 months after completion of antibiotic treatment. Symptoms include fatigue, myalgias, arthralgias (without arthritis), and mood and memory disturbances (which can be shown through neuropsychological testing). Steere et al30 suggest that these
PREVENTION
Avoidance of tick bites is the most obvious means to prevent B burgdorferi infection. If people must be outside in areas where Ixodes ticks are found, they are advised to wear protective clothing and tick repellent containing N,N-diethyl-m-toluamide (DEET). Frequent skin inspection and prompt removal of ticks should also decrease the risk of infection. However, data regarding the efficacy of these measures are limited. Other measures, including burning or removal of vegetation in tick-harboring
CONCLUSION
Lyme disease is not uncommon and may affect people who spend time outdoors, especially in areas where Lyme disease is endemic. Affected people typically present with nonspecific symptoms and the characteristic erythema migrans rash; unfortunately, only 50% to 70% of patients recall a tick bite and thereby alert the physician to the diagnosis. Physicians should have a high index of suspicion for Lyme disease in areas known to harbor the disease. Prompt treatment with antibiotic therapy helps
REFERENCES (31)
Prevention of Lyme disease: a review of the evidence
Mayo Clin Proc
(2001)Cardiac manifestations of Lyme disease
Med Clin North Am
(2002)- et al.
Laboratory testing for suspected Lyme disease
Med Clin North Am
(2002) Erythema migrans
Med Clin North Am
(2002)Centers for Disease Control and Prevention Web site
- et al.
The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America
Clin Infect Dis
(2006 Nov 1) - et al.
Lyme disease, II: clinical features and treatment
Cutis
(2002) - et al.
Occupational risk of Lyme disease: an epidemiological review
Occup Environ Med
(2002) - et al.
Lyme disease
Curr Opin Rheumatol
(2001) Lyme disease: an update
Curr Allergy Asthma Rep
(2001)
Lyme disease in children
Curr Opin Rheumatol
Lyme disease: United States, 1996
MMWR Morb Mortal Wkly Rep
Bitten: what every hiker needs to know about Lyme disease
Backpacker
Cited by (129)
Merging Patches, an Atypical Presentation of Disseminated Cutaneous Lyme Disease: A Case Report
2020, Journal of Emergency MedicineCitation Excerpt :Testing for the presence of Lyme disease is of limited use in the patient presenting with signs and symptoms of Lyme with a tick exposure. In patients with an unclear history of exposure or signs and symptoms of Lyme disease, the Centers for Disease Control and Prevention recommends a two-step testing process (5). Whereas two-tiered testing has a sensitivity of only 30–40% in the early stages of Lyme, as the disease progresses, the sensitivity of the test rises to 70–100% in disseminated Lyme (6).
Rodent species as possible reservoirs of Borrelia burgdorferi in a prairie ecosystem
2019, Ticks and Tick-borne DiseasesCitation Excerpt :Lyme borreliosis is the most commonly diagnosed tick-borne disease in both the United States and Europe (Bratton et al., 2008; Stanek et al., 2011).
Lyme disease: An overview
2023, Indian Dermatology Online JournalBorrelia miyamotoi: A Comprehensive Review
2023, PathogensBLOOD BIOCHEMICAL PARAMETERS IN RESERVOIR HOSTS UNDER IXODID TICK-BORNE BORRELIOSIS
2023, Sel'skokhozyaistvennaya Biologiya