Lyme Disease in Emergency Medicine Clinical Presentation

Because only about 25-30% of patients with Lyme disease recall the bite, history taking must be directed toward determining the epidemiologic probability of a tick bite. Because Lyme disease can affect many body parts, many presenting complaints can exist. Though imperfect, the various stages if Lyme disase and the associated timeline are helpful.

Systemic manifestations

Fever is generally low grade. A high-grade fever or toxic appearance suggests co-infection, such as ehrlichiosis or babesiosis, or an alternative diagnosis.

Fatigue is common. Nausea and vomiting are reported.

Myalgias and arthralgias occur early. Frank arthritis (ie, joint swelling, redness, pain) usually is a later manifestation but can occur in the early disseminated phase.

Flulike illness (undifferentiated febrile illness) may occur. Although the frequency of this is unknown, the phenomenon of Lyme disease with typical flulike symptoms of fevers, chills, myalgias, arthralgias, and malaise (without rash) is well documented. The season of onset, epidemiologic likelihood of a tick bite, paucity of respiratory and GI symptoms, and prompt response to antiborrelial therapy are diagnostic clues.

Cutaneous symptoms

The classic rash, erythema migrans (EM), is present in about 75% of patients. Because it is neither pruritic nor painful (although it can be either), some patients may have the rash but not notice it. EM can occur in the same patient more than once. This rash is shown in the image below.

About 20% of patients with Lyme disease have multiple lesions (from hematogenous dissemination). The higher figure is from earlier studies; current information suggests that the rate of multiple lesions is closer to 20%.

Borrelial lymphocytoma, a nodule usually found on the ear lobe or areola of the nipple, develops in some patients early in the course of disease. This is more common in Europe.

Almost exclusively observed in Europe, acrodermatitis chronicum atrophicans is a rash that patients describe as inflammation or thinning of the skin, usually on the distal legs and hands.^[8]

Neurologic symptoms

Headache can occur in early infection as a nonspecific finding and can herald CNS penetration and lymphocytic meningitis. The headache of Lyme disease typically is described as waxing and waning, and the severity varies from mild to severe, even in patients with frank meningitis.

Patients notice facial weakness, which is similar to a typical Bell palsy and which can be the presenting symptom of Lyme disease. About 25% of patients with borrelial facial palsy have bilateral involvement, which may be sequential and is a point of differential diagnostic significance. Other than Lyme disease and Guillain-Barré syndrome, bilateral seventh nerve palsy is rare.

In an analysis of 313 children with facial palsy, 34% were due to Lyme disease. Clinical predictors were onset of symptoms between June to October, absence of herpetic lesions, presence of fever, and history of headache.^[9]

Radicular pain can occur and present as acute disk disease. More common in European patients, radicular pain may be associated with lymphocytic pleocytosis (Bannwarth syndrome).

Late Lyme disease can cause paresthesias or pain due to peripheral neuropathy and personality, cognitive, and sleep disturbances from chronic encephalopathy. All sorts of neurologic syndromes caused by Lyme disease involving nearly every part of the CNS and peripheral nervous system have been reported in numerous case reports; therefore, Lyme disease may produce numerous symptoms. Although the likelihood that these other symptoms result from Lyme disease in any particular patient may be small, the clinician must remain open minded to this possibility.

Cardiovascular involvement

Cardiovascular involvement occurs in fewer than 10% of patients with untreated Lyme disease and is more common in male patients than in female patients.

Palpitations, lightheadedness, and syncope may be a manifestation of varying degrees of heart block, including complete heart block, which occurs in 50% of patients with cardiac involvement. Lyme disease is an important reversible cause of heart block.^[10]

Chest pain and dyspnea can occur in the setting of Lyme pericarditis, myocarditis, and myopericarditis. Cardiac tamponade has been reported.

Joint involvement

Migratory pain may occur from myositis, tendonitis, and bursitis. These symptoms classically wax and wane over hours or days. Later, arthritis occurs generally with swelling, redness, and pain in one or a few large joints, typically the knees. Synovitis occasionally occurs in the early-disseminated phase of Lyme disease.

Ocular invovlement

Red, itchy eyes are the most common ocular symptom. Blurred vision and eye pain can occur from keratitis and iritis. Unilateral blindness from panophthalmitis has been reported as well.

The physical examination in patients with Lyme disease can reveal numerous findings, depending on the target organs involved and the phase of the disease at presentation. In addition to fever, other findings are described below.

Dermatologic findings

Classic EM is an erythematous papule or macule that occurs at the site of the tick bite (1-33 d later; average, 7-10 d). Often, a central punctum is found at the site. The size varies enormously (as large as 70 cm; average, 16 cm) and depends on disease duration. Central clearing, a phenomenon emphasized in earlier literature, occurs in only a minority of cases in North America (about 40% in one study of culture-proven EM).^[11] Central clearing is more common in European patients than in North American patients.

Although lesions are defined, for surveillance purposes, as being greater than 5 cm in size, smaller lesions that are culture positive for B burgdorferi have been reported. EM may not be pathognomonic for Lyme disease; similar lesions are found in patients with a similar tick-borne disease found across the southern United States. In this disease, called southern tick-associated rash illness (STARI), or Master disease, a similar rash is seen. While differences exist between the two rashes as a group, significant overlap exists in individual cases.

EM usually is flat, round, or oval and monocyclic. Generally, neither itching nor pain is present. The rash enlarges a few centimeters per day and fades, even if untreated, after a few weeks. The rash can be triangular or linear and is sometimes fleeting in duration. Rash location is another important diagnostic clue.^{[3, 12]}

The clinician must be able to recognize atypical manifestations of EM, such as necrotic and vesicular lesions. The lesion may have central darkening or be uniform in color, and the edges may be raised. Scaling is unusual.

EM rarely is found on the hands and feet (unlike spider and other arthropod bites). Ticks tend to bite where natural barriers impede their forward motion (eg, axillary or gluteal folds (shown in the image below), hairline, areas near elastic bands in bra straps or underwear). In children, the scalp, face, and hairline are more common locations.

Approximately 20% of patients with EM have secondary lesions. These lesions generally are smaller than the primary one, lack the central punctum, and are not necrotic or vesicular.

Borrelial lymphocytoma most frequently is observed in European patients. This finding can be early or late and can follow or occur concurrently with EM. It is a reddish purple nodule on the ear lobe or the nipple (other locations are possible).^[8]

Acrodermatitis chronicum atrophicans (shown in the image below) is nearly exclusively observed in European patients. The two phases are an inflammatory phase with edema and erythema in the distal extremities and a scarring phase with atrophy and skin as thin as cigarette paper. B burgdorferi has been cultured from lesions in which the primary infection occurred over 10 years prior.

Neurologic signs

Neck stiffness can occur early, with or without frank meningitis.

Facial nerve palsy is a lower motor neuron lesion that causes facial weakness of both the lower face and forehead. It can be bilateral. As in idiopathic Bell palsy, sometimes a polycranial neuropathy exists with any nerve involved; this more commonly is reported in the European literature. Nearly every cranial nerve has been reported to be involved, although this is uncommon.

Weakness and abnormal sensation can occur because of meningoradiculitis and more commonly is reported in European patients. Diminished reflexes can occur with this syndrome. CSF frequently reflects pleocytosis.

Neuropsychiatric testing and mini-mental status testing may uncover cognitive, memory, and personality changes that occur in late Lyme encephalopathy.

Peripheral axonal neuropathy can lead to patchy, generally distal abnormalities in sensation. Sensory findings are more pronounced than motor findings.

Cardiovascular findings

In patients with complete heart block, Canon A waves may be observed in the neck. A slow or irregular pulse may be palpated.

A cardiac rub, S₃ and/or S₄, may be auscultated in patients with myocarditis or pericarditis. Signs of tamponade very rarely can occur. In patients with chronic cardiac involvement with congestive heart failure, typical signs of congestive heart failure may be present.

Musculoskeletal findings

Muscle tenderness can result from myositis; tenderness of tendons and periarticular structures may be present.

Frank arthritis can occur after weeks, months, or years and may lead to erythema, edema, synovial effusion, and tenderness of the affected joints. Usually, this is a monoarthritis or oligoarthritis involving large joints, especially the knee. Swelling often is disproportional to the tenderness.

Ocular signs

Conjunctival erythema and injection or retinal hemorrhages and exudates may be present. On slit-lamp examination, signs of keratitis and cells in the anterior chamber from iritis may be seen. In children (especially in North America), papilledema may be present in a pseudotumor cerebri–like syndrome.

Other signs

Other signs can include splenomegaly, hepatomegaly, and regional lymphadenopathy.

Lyme disease is caused by infection with the spirochete, B burgdorferi, the complete genome of which has been described recently. B burgdorferi is shown in the image below.

The species Borrelia burgdorferi sensu lato has several well-characterized groups that may lead to different clinical manifestations. These 3 groups are B burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii. Other strains, which may be sufficiently different in their genetic structure to be considered separate strains, exist; however, most of these are nonpathogenic to humans. This is an area of active research.

B burgdorferi sensu stricto is present in most North American isolates. B afzelii is common in Europe and is frequently isolated in patients with acrodermatitis chronicum atrophicans. B garinii, more common in Europe, is commonly isolated in patients with lymphocytic meningoradiculitis (Bannwarth syndrome) and white matter encephalitis.

Occupational or recreational activities that place an individual in contact with ticks are the major risk factors.

Arthritis that is nonresponsive to antibiotics may develop in some genetically predisposed individuals (ie, those who have the HLA-DR4 antigen).

Some patients will have persistent or recurrent symptoms after what is considered adequate antibiotic therapy for Lyme disease. This phenomenon has been termed chronic Lyme disease, or post-Lyme syndrome. The cause for this is controversial.^{[2, 13]}