27 - 179 - LYME BORRELIOSIS Flashcards
causative agent of Lyme disease
Borrelia burgdorferi
most common cutaneous finding of lyme disease
erythema migrans rash.
major tick vector in the US
Ixodes scapularis
primary amplifying host of B. burgdorferi
white-footed mouse
main vector of B. burgdorferi in Asia
Ixodes persulcatus
first symptom to develop with lyme disease infection
erythema migrans (EM) rash
begins 3 to 30 days (average: 7 days) after completion of tick feeding
bacteria can disseminate from the inoculation site as early as how many days after the presence of the original EM lesion?
3 days
The most common manifestation of hematogenous dissemination of the spirochete
**multiple EM rashes, **which are scattered over the body
2 phases of Acrodermatitis Chronica Atrophicans seen in lyme disease
**1. Inflammatory Phase **
* bluish-red discoloration on the extensor aspect of fingers, hands, joints, and lower extremities
* usually involved joints: elbows and knees
* Associated findings include a **cushion-like (“doughy”) swelling of the dorsum **of the hands and feet
* swelling of the posterior aspect of the lower extremities is believed by some to be particularly indicative of Lyme disease
2. Atrophic Phase
* lesions with a** “cigarette paper-like” appearance and a prominence of superficial veins
* Chronic joint and bone involvement, attributed to persistence of spirochetes in cutaneous lesions, is most often seen in patients with longstanding ACA or an untreated lesion of EM or ACA and is typically restricted to the extremity involved
* characteristic symptom, exhibited in approximately one-third of patients in one study, was a swollen or painful foot and heel**
- These are sclerotic skin lesions clinically indistinguishable from primary lichen sclerosus et atrophicus or morphea
- Periarticular (“ulnar”) fibrous nodules described in association ACA, may also occur in the absence of dermatoborrelioses.
- They usually present as hard nodules on the elbows and knees, and on the lateral aspect of the digits near joints, and have been reported to be provoked by trauma, surgery, and electromagnetic radiation.
Cutaneous Scleroborrelioses
Uncommon sclerotic disorders associated with Lyme disease
- Parry-Romberg syndrome: progressive facial hemiatrophy
- Shulman syndrome: eosinophilic fasciitis
most common neurologic manifestations of lyme disease
These can manifest as soon as 1 week after EM
Meningitis, cranial neuropathy, and radiculopathy
most characteristic neuropathy of early Lyme disease in the United States
Facial palsy
neurologic manifestations pathognomonic for Lyme disease
- triad of lymphocytic meningitis,
- cranial palsy (often facial), and
- radiculoneuritis, known as Bannwarth syndrome
Within the heart, B. burgdorferi has a predilection for what structure?
this results in what sequelae?
Within the heart, B. burgdorferi has a predilection for the atrioventricular node, resulting in** atrioventricular block**
most frequent clinical sign of late-disseminated Lyme disease in the United States, occurring in approximately 60% of patients with untreated or incompletely treated infection
Inflammatory arthritis
main laboratory modality used to support a clinical diagnosis of Lyme disease
Immunologic diagnosis
(enzyme-linked immunoabsorbent (ELISA) and Western immunoblot assays)
Approach to patient with erythema migrans
- generally considered as first-line therapy for lyme disease
- what is the alternative first-line agent?
- what are second-line agents for lyme disease?
- Doxycycline
- Cefuroxime
- Macrolides
- Doxycycline should be used in children and pregnant women
- Duration of therapy for EM is generally recommended to be 10 to 14 days
antibiotics that may be recommended for patients with cutaneous manifestations that are accompanied by neurologic disease (meningitis, encephalopathy) or high-degree heart block
IV antibiotics (ceftriaxone, cefotaxime, or penicillin G)
it is thought that there is minimal transmission of spirochetes before how many hours of attachment and feeding?
36 hours
Under certain conditions if an attached tick is found, what prophylactic antibiotic can be given?
Doxycycline 200 mg × 1 dose
