Lyme Disease
B. Denise Hemby and Theresa M. Campo
Definition
A.Lyme disease (LD) is the most common vector-borne illness in the United States. It is a multisystem illness usually caused by the spirochete Borrelia burgdorferi that is carried and spread by several types of ticks. In 2015, it was the sixth most commonly reported disease. LD is transmitted to humans via the bite of an infected tick. Ticks can attach to any part of the body but are found in hard to see areas like the groin, armpits, scalp, and back. There is not a minimum attachment time but the longer the attachment, the greater risk or likelihood of acquiring the infection. Generally, it is 36 to 48 hours or longer before B. burgdorferi can be transmitted.
B.Morbidity from LD usually involves neurologic and cognitive dysfunction. There is a subset of patients treated for LD with a recommended 2- to 4-week antibiotic regimen that experience some symptoms of post-LD symptoms. Posttreatment Lyme disease syndrome (PTLDS) includes cognitive disturbances, fatigue, joint/muscle pain, headaches, hearing loss, vertigo, mood disturbances, paresthesias, and difficulty sleeping.
C.There is no evidence that LD is transmitted from person to person or from pet to person, or spread via the air, food, or water or via bites from mosquitoes, flies, fleas, and lice. B. burgdorferi can live in blood that is stored for donation but after completing the antibiotic treatment, blood donation may be considered.
Incidence
A.LD is the most common tick-borne disease in the Northern Hemisphere. It does occur most heavily in the Northeast and upper Midwest. In 2015, 95% of confirmed LD cases were reported from 14 states (CT, DE, ME, MD, MA, MN, NH, NJ, NY, PA, RI, VA, VT, WI). The 2015 U.S. incidence rate of total cases was 8.9 confirmed cases per 100,000 people. Age distribution is bimodal; the peak is in children aged 5 to 14 years and the second in adults aged 45 to 54 years.
B.LD has a seasonal influence that reflects the feeding patterns of tick. Infections occur most often between May and November, with a peak incidence in June through August with 75% of cases occurring during the summer months.
Pathogenesis
A.B. burgdorferi, a spirochete bacterium, is an infectious agent carried by several types of ticks. The ticks bite mice or deer that are infected with B. burgdorferi, and infect humans with their bites. The blacklegged tick or deer tick, Ixodes scapularis, spreads the disease in the northeastern, mid-Atlantic, and north-central United States. The western black-legged tick, Ixodes pacificus, spreads the disease on the Pacific Coast of the United States. The life cycle of blacklegged ticks is 2 years and it goes through four life stages: egg, six-legged larva, eight-legged nymph, and adult. Once hatched, the tick must have a blood meal to survive. Once infected, a tick can transmit infection throughout its life. Rodents and pets can also harbor deer ticks.
B.The spirochete enters the bloodstream at the time of tick feeding. The incubation period is 3 to 32 days, or about 1 to 3 weeks after bite. Late manifestations occur several months to more than 1 year later.
Predisposing Factors
A.People of all ages are affected.
B.Recreational exposure.
1.Hiking, golfing, hunting, soccer.
C.Gardening.
D.Exposure to rodents such as field mice and domestic pets, which may also carry the ticks.
Common Complaints
A.Fever, chills, flu-like symptoms.
B.Fatigue.
C.Headache.
D.Joint pain.
E.Muscle aches.
F.Swollen lymph nodes.
G.Rash or lesion at site of tick bite.
Other Signs and Symptoms
A.Stage 1: Acute early localized-beginning days or weeks (1–30 days) after infection:
1.Rash: Erythema migrans—bull’s eye
—flat or slightly raised red area at the site of the tick bite.
It usually begins as a red macule at the site of the tick bite and spreads out to form a large annular lesion with red secondary outer rings, an intense red outer border (measuring at least 5 cm), and some clearing at the site of the bite. Appearance is a bull’s-eye
shape. The lesion is generally painless and not pruritic.
2.Body aches.
3.Fever or chills.
4.Swollen lymph nodes.
B.Stage 2: Disseminated infection (early disseminated)—develops 3 to 10 weeks after infection:
1.Fever, alaise, debilitating fatigue.
2.Headache.
3.Photophobia.
4.Mild neck stiffness.
5.Joint or muscle pain.
6.Migratory arthralgia.
7.Rash: Diffuse erythema.
8.Itching.
9.Transient heart block:
a.In 5% to 10% of cases, patients have cardiac involvement: A transient heart block ranging from asymptomatic, first-degree atrioventricular (AV) block to complete heart block with fainting. The cardiac phase lasts 3 to 6 weeks.
10.Bell’s palsy:
a.A unilateral or bilateral Bell’s palsy is the most common cranial nerve deficit.
11.Mild encephalopathy.
C.Stage 3: Chronic (late disease)—occurs months to years after initial infection:
1.Prolonged arthritis—hallmark of stage 3.
a.Approximately 60% of complaints evolve into frank arthritis. Onset of arthritis is variable but averages 6 months from the time of initial infection. It tends to involve large joints; the knee is the most common (90%) site and the pattern continues to be oligoarticular.
2.Chronic neurologic deficits.
3.Distal paresthesia.
4.Radicular pain.
5.Memory loss.
Subjective Data
A.Review the onset, course, and duration of symptoms.
B.Ask the patient about any recent outdoor activities, such as camping, hiking, gardening, or other activities. Less than half of the people infected remember a tick bite. A history of a tick bite is not necessary for diagnosis.
C.Have other family members had similar symptoms?
D.Review thorough history of medications.
E.Review any history of rash and course of spread.
F.Rule out late symptoms associated with LD such as arthritis, memory loss, and distal paresthesia.
G.Has the patient been previously treated for LD or Rocky Mountain spotted fever (RMSF)?
Physical Examination
A.Check temperature, pulse, respirations, and blood pressure.
B.Inspect:
1.Observe general overall appearance.
2.Observe rash pattern and type.
3.Inspect the skin; observe for target-like pattern.
C.Palpate:
1.Palpate the lymph nodes and mastoid bones.
2.Examine the joints for tenderness, swelling, and range of motion.
D.Auscultate: Auscultate the heart and lungs.
E.Neurologic exam: Evaluate for signs of meningeal irritation by means of Brudzinski’s sign and Kernig’s signs (see Figures 19.1 and 19.2):
1.Brudzinski’s sign: Place the patient supine, one hand on the patient’s chest, one hand behind the patient’s head, and flex the head upward. Flexion of lower extremities (hip and knees) is a positive sign and resulting flexion indicates meningeal irritation.
2.Kernig’s sign: Place the patient supine. Keeping one leg straight, flex the other hip and knee to a bent knee to form a 90-degree angle, then completely extend the leg at the knee joint. This places a stretch on the meninges, resulting in pain. If the leg cannot be completely extended, this is a positive Kernig’s sign.
Diagnostic Tests
A.Immunoblot Tests (Figure 19.3).
B.Immunoglobulin M (IgM)—acute, needs to be done in first few weeks.
C.Immunoglobulin G (IgG)—more reliable, can take 4 to 6 weeks for body to produce enough to detect.
Other Tests to Rule Out Other Infections
A.Complete blood count (CBC) with differential:
B.Comprehensive metabolic panel—alanine transaminase (ALT) and aspartate transaminase (AST; may be mildly elevated).
C.Sedimentation rate.
D.Arthrocentesis for joint effusion—chronic/late disease.
E.PCR testing.
F.Creatine phosphokinase.
G.Lumbar puncture indicated for the presence of neurological symptoms.
Differential Diagnoses
A.LD.
B.Insect or spider bite.
C.RMSF.
D.Ehrlichiosis.
E.Tularemia.
F.Cellulitis.
G.Arthritis.
H.Bacterial meningitis.
I.Chronic fatigue syndrome (CFS).
J.Viral syndrome.
K.Nummular eczema.
L.Tinea corporis (ringworm).
Plan
A.General interventions.
B.
See Section III: Patient Teaching Guide Lyme Disease and Removal of a Tick
:
1.Not all neurologic signs and symptoms may completely resolve (such as headache, photophobia, Bell’s palsy, and third-stage symptoms).
2.Patients with active LD should not donate blood because spirochetemia occurs in early LD. Patients who have been treated for LD in the past can be considered for blood donation.
3.Currently there is no vaccine for LD. The vaccine was withdrawn in early 2002. Previously vaccinated patients are not protected against LD.
4.Nonspecific symptoms may persist for months after treatment of LD. There is no evidence that chemoprophylaxis the complaints represent ongoing active infection or need repeated antibiotics:
a.Headache.
b.Fatigue.
c.Arthralgias.
C.Pharmaceutical therapy.
NOTE: The Infectious Disease Society of America (IDSA) 2006 guidelines state that for Lyme disease be given if a patient meets the criteria:
1.Tick attached greater than 36 hours.
2.Tick identified.
3.Infection rate is greater than 20% in local area.
4.No contraindications to doxycycline:
For chemoprophylaxis in patients age older than 8, one-time dose of doxycycline 200 mg.
Treatment for early LD with erythema migrans.
D.Early localized LD—with erythema migrans:
1.Doxycycline:
a.Adults: 100 mg PO BID for 14 days OR
2.Amoxicillin:
a.Adults: 500 mg PO TID for 14 days OR
3.Cefuroxime:
a.Adults: 500 mg PO BID for 14 days.
E.LD with neurologic involvement:
1.Ceftriaxone (Rocephin). Adults: 2 g/d intravenous (IV) for 14 days OR
2.Cefotaxime:
a.Adults: 2 g IV every 8 hours for 14 days OR
3.Penicillin G:
a.Adults: 18 to 24 million U/d IV divided doses every 4 hours for 14 days OR
4.Doxycycline:
a.Adults: 200 to 400 mg/d PO/IV BID for 10 to 28 days.
5.Pregnant women:
a.For localized early LD, amoxicillin 500 mg three times daily for 21 days.
b.For disseminated early LD or any manifestation of late disease, penicillin G 20 million units daily for 14 to 21 days.
c.For asymptomatic seropositivity, no treatment is necessary.
F.The Jarisch–Herxheimer reaction (JHR); onset 24 to 72 hours after initiating antibiotics and can last for weeks. JHR occurs when there is accelerated phagocytosis of the spirochetes, causing a rise in cytokines. Symptoms include increased fever, muscle, joint, and body pain, headache, low blood pressure, and elevated heart rate. It is a normal part of treatment for late stage/chronic LD. Symptoms should be closely monitored. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be beneficial, and the antimicrobial agent should be continued.