II. Pathophysiology

  1. Deer Tick (Ixodes Scapularis) Image derived from CDC
    1. IDVectorDeerTicks.jpg
  2. Deer Ticks have four stage life cycle over 2 years
    1. Egg
    2. Larva
    3. Nymph (most common form to transmit disease)
    4. Adult
  3. Transmission of disease
    1. Transmission unlikely before attached for 1-2 days
    2. Engorged nymph most likely to transmit disease

III. Pathophysiology: Diseases transmitted by the Deer Tick

IV. Differential Diagnosis

  1. American Dog Tick (Dermacentor variabilis)
    1. Twice the size of Deer Ticks
    2. Not associated with Lyme Disease
    3. Associated with Babesiosis

V. Management: Deer Tick Bite

  1. Prompt Tick Removal
    1. See Tick Removal
    2. Infection transmission 1% at under 24 hours
    3. Infection transmission 20% at over 72 hours
  2. Observe for Tick Borne Illness for 30 days after bite
    1. Erythema Migrans (Lyme Disease)
    2. If fever occurs, consider additional conditions
      1. Babesiosis
      2. HGA (previously known as Ehrlichiosis)
  3. Antibiotic Prophylaxis After Known Deer Tick Bite
    1. Routine prophylaxis not recommended
    2. Following known deer Tick Bite in endemic area
      1. Early Lyme DiseaseIncidence: 1.2%
    3. Antibiotics after deer Tick Bite in endemic area
      1. Doxycycline
        1. Dose within 72 hours of Tick Bite
          1. Adults: 200 mg orally for one dose
          2. Child >8 years: 4 mg/kg (max: 200 mg) orally for one dose
        2. Efficacy in preventing Lyme Disease: 87%
        3. References
          1. Nadelman (2001) N Engl J Med 345:133-4 [PubMed]
      2. No other antibiotic is indicated in prophylaxis
        1. Prior study showed some efficacy with Amoxicillin
          1. Shapiro (1992) N Engl J Med 327:1769 [PubMed]

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Related Studies

Ontology: Ixodes dammini (C0282508)

Concepts Eukaryote (T204)
SnomedCT 39437005, 76387006
English eastern deer tick, Ixodes dammini, deer tick, deer ticks, ixodes dammini, Ixodes dammini (organism), Eastern deer tick, Northern deer tick
Spanish pulga del ciervo oriental, Ixodes dammini (organismo), Ixodes dammini, garrapata de patas negras, garrapata de los ciervos

Ontology: Ixodes scapularis (C0282510)

Concepts Eukaryote (T204)
MSH D018884
SnomedCT 76387006
LNC LA19250-2
Portuguese Ixodes scapularis, Carrapato do Veado, Ixodes dammini, Carrapato de Patas Pretas
French Ixodes scapularis, Tique à pattes noires, Tique du daim, Ixodes dammini, Tique du chevreuil
German Ixodes scapularis, Schwarzbeiniger Holzbock
English Ixodes scapulari, scapulari, Ixodes, Black legged Tick, Black-legged Ticks, Ticks, Black-legged, scapularis, Ixodes, Tick, Black-legged, Deer Ticks, Ixodes dammini, Tick, Deer, Ticks, Deer, damminus, Ixodes, Deer Tick, Ixodes damminus, dammini, Ixodes, Ixodes scapularis, ixodes scapularis, black legged ticks, Ixodes scapularis Say, 1821, deer tick, Black-legged Tick, blacklegged tick, shoulder tick, Ixodes scapularis (organism), black legged tick, Black-legged tick
Spanish Garrapata del Venado, Ixodes dammini, Ixodes scapularis (organismo), Ixodes scapularis, Garrapata de Piernas Negras
Norwegian Ixodes scapularis
Dutch Ixodes scapularis, Hertenteek

Ontology: Ixodes pacificus (C0323408)

Concepts Eukaryote (T204)
SnomedCT 592002
English Ixodes pacificus Cooley & Kohls, 1943, California black legged tick, Ixodes pacificus, Ixodes pacificus (organism)
Spanish Ixodes pacificus (organismo), Ixodes pacificus