Pediatric Lyme Disease Clinical Presentation

Most patients with Lyme disease do not recall a tick bite. The clinical presentation depends on the stage at which the disease is recognized: (1) early disease, (2) early disseminated disease, or (3) late disease.

Early disease

Early disease usually develops 7-14 days after a tick bite. Two thirds of patients with Lyme disease present with the typical rash, erythema migrans (EM).^[2] The rash may be a confluent patch of erythema or may have central clearing. The rash typically expands over days and is not evanescent. EM is a clinical diagnosis, and serologic testing for children with a single EM lesion is generally not recommended because patients may be seronegative early in the course of illness.

During early disease, with or without the rash, patients may complain of a flulike illness characterized by fever, chills, myalgias, arthralgias, headache, and malaise. In the area of the tick bite, tender adenopathy may be noted.

Early disseminated disease

Early disseminated disease usually develops 3-10 weeks after inoculation. Approximately 25% of individuals infected with B burgdorferi have signs and symptoms of disseminated disease at presentation.

Multiple EM lesions are present. These are relatively small erythematous macules (1-5 cm) and are often oval. Unlike primary single EMs, these lesions can be evanescent and do not show the typical expansion over days.

Patients with early disseminated disease may complain of fever, myalgias, arthralgias, malaise, and headache. Persistent headache alone is a rare presentation of Lyme disease but should be considered in patients in endemic areas during summertime.

Cranioneuropathies, especially peripheral seventh nerve palsy (Bell palsy), are common (3% of Lyme disease). In endemic areas, Lyme disease is the most commonly identified cause of acquired facial palsy, especially in children^[3] Headache, absence of previous herpetic lesions, and meningeal symptoms are noted in most pediatric Lyme disease patients with facial palsy.

Aseptic meningitis may develop at this stage. Encephalitis is rare. Carditis may present as complete heart block.

Late disease

Late disease develops weeks to months after inoculation. Its hallmark is arthritis, which tends to involve large joints (the knee is involved in 90% of cases). Arthritis must be differentiated from arthralgia, which is common in early disease.

Most patients presenting with late disease do not have a history of EM, because the rash typically leads to earlier treatment, which prevents the development of late disease.

Early disease

Physical findings in patients with early disease are as follows:

• EM rash - Confluent or central clearing, expands over days, not evanescent, more common on head or neck in young children and on extremities in older children, characteristic large (>2 cm) macules, which are round or oval and may be more difficult to recognize on the face, neck, or axilla
• Fever
• Myalgias
• Malaise
• Arthralgia
• Patient appears in discomfort due to headache or myalgias
• Tender adenopathy (local, not diffuse)

Early disseminated disease

Physical findings in patients with early disseminated disease are as follows:

• Multiple EM lesions: Twenty-five percent of patients with Lyme disease present with multiple EM. Eighty-nine percent of patients with disseminated Lyme disease present with at least one EM lesion.
• Headache
• Fever
• Tender adenopathy (regional or generalized)
• Conjunctivitis (uncommon, never prominent)
• Carditis (usually manifests as heart block)
• Meningismus as a sign of aseptic meningitis
• Cranioneuropathy, especially cranial nerve VII and Bell palsy (peripheral seventh nerve palsy with decreased unilateral function, including the forehead)

Late disease

In patients with late disease, the typical physical finding is arthritis. Arthritis is located mostly in large joints, especially the knee. Warmth, swelling from effusion, and limited range of motion help distinguish arthritis from simple arthralgia.

The agents responsible for babesiosis and ehrlichiosis share the same tick vector as B burgdorferi, making co-infection possible. Severe and even fatal acute infection caused by these agents is more common in asplenic individuals (babesiosis) or older adults (Ehrlichia); however, unlike B burgdorferi, chronic infection by these agents is not observed. To add to the confusion, ehrlichial infection may cause a false-positive result for Lyme disease on immunoglobulin M (IgM) Western blot analysis.

One nonmedical complication of Lyme disease has been the public and media’s misconceptions about the disease. Unfortunately, many clinicians perform too many tests when the prior probability of disease is low, resulting in many false-positive tests.

The combination of nonspecific symptoms and suboptimal test results has led to overtreatment for suspected (but not proven) Lyme disease and to the concept of refractory Lyme disease.

Go to Ophthalmic Aspects of Lyme Disease for complete information on this topic.