Rocky mountain spotted fever: Difference between revisions
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==Background== | ==Background== | ||
*Most frequent rickettsial disease reported in the US. | [[File:American dog tick.jpeg|thumb|American dog tick]] | ||
*Most frequent rickettsial disease reported in the US.<ref name="http://www.cdc.gov/rmsf/">http://www.cdc.gov/rmsf/</ref> | |||
*Caused by Rickettsia rickettsii | *Caused by Rickettsia rickettsii | ||
**Obligate intracellular, gram negative bacteria | **Obligate intracellular, gram negative bacteria | ||
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*Widely distributed in the US | *Widely distributed in the US | ||
**States with the highest incidence are Oklahoma, Nebraska, Arkansas, Tennessee and North Carolina | **States with the highest incidence are Oklahoma, Nebraska, Arkansas, Tennessee and North Carolina | ||
*Overall incidence is increasing while mortality is falling | *Overall incidence is increasing while mortality is falling<ref>Columbia University Irving Medical Center. Rocky Mountain Spotted Fever. https://www.columbia-lyme.org/rocky-mountain-spotted-fever.</ref> | ||
**Prior to the era of antibiotics, ~30% mortality | |||
**Currently mortality is 3-5% | |||
==Clinical Features== | ==Clinical Features== | ||
*Symptoms generally begin 2-14 days after inoculation from an infected tick | *Symptoms generally begin 2-14 days after inoculation from an infected tick<ref>http://www.mayoclinic.com/health/rocky-mountain-spotted-fever/DS00600</ref> | ||
===Early symptoms=== | ===Early symptoms=== | ||
*'''Non specific and highly variable''' | *'''Non specific and highly variable''' | ||
*Fever | *[[Fever]] | ||
*Nausea/Vomiting | *[[Nausea/Vomiting]] | ||
*Abdominal pain | *[[Abdominal pain]] | ||
* | *[[Myalgia]]s (severe calf pain) | ||
*Headache | *[[Headache]] | ||
*Fatigue | *[[Fatigue]] | ||
*Conjunctivitis | *[[Conjunctivitis]] | ||
===Late symptoms=== | ===Late symptoms=== | ||
[[File:Rocky Mountain Spotted Fever Rash.jpg|thumb|Rocky mountain spotted fever rash]] | |||
*Rash | *[[Rash]] | ||
**Begins as a blanching maculopapular rash that evolves to become a petechial rash | **Begins as a blanching maculopapular rash that evolves to become a petechial rash | ||
**Usually 2-5 days after fever subsides | **Usually 2-5 days after fever subsides | ||
**Starts on extremities and spreads inward (centripetally) | **Starts on extremities and spreads inward (centripetally) | ||
**Can involve palms and soles (50% of cases) | **Can involve palms and soles (50% of cases) | ||
*[[Arthralgia]]s | |||
*Positive Rumpel-Leede test | *Positive Rumpel-Leede test | ||
**Development of petechiae at the site of blood pressure cuff and distally after compression | **Development of petechiae at the site of blood pressure cuff and distally after compression | ||
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===Complications=== | ===Complications=== | ||
*Secondary to host response against infected endothelial cells | *Secondary to host response against infected endothelial cells | ||
**Vasculitis | **[[Vasculitis]] | ||
**Myocarditis | **[[Myocarditis]] | ||
**Interstitial pneumonitis | **Interstitial [[pneumonitis]] | ||
**Encephalitis | **[[Encephalitis]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
*Other [[Tick Borne Illnesses]] | *Other [[Tick Borne Illnesses]] | ||
*Non-specific viral illness | *Non-specific [[viral syndrome|viral illness]] | ||
{{Lower respiratory zoonotic infections}} | {{Lower respiratory zoonotic infections}} | ||
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{{Tick borne illnesses DDX}} | {{Tick borne illnesses DDX}} | ||
== | ==Evaluation== | ||
* | *PCR (initially) | ||
* | *Serial serologic examinations by indirect fluorescent antibody confirm the diagnosis | ||
* | *Titers | ||
== | ===Work-Up=== | ||
*[[ | *[[ECG]] ([[Myocarditis]]) | ||
*Chem 7 ([[Hyponatremia]]) | |||
*CBC ([[Thrombocytopenia]]) | |||
== | ==Management== | ||
{{Rocky Mountain Spotted Fever antibiotics}} | |||
==Disposition== | |||
==See Also== | |||
*[[Tick borne illnesses]] | |||
==References== | |||
<references/> | |||
[[Category:ID]] | [[Category:ID]] |
Latest revision as of 03:51, 27 November 2019
Background
- Most frequent rickettsial disease reported in the US.[1]
- Caused by Rickettsia rickettsii
- Obligate intracellular, gram negative bacteria
- Predilection for vascular endothelial cells
- Spread by ticks
- American Dog Tick (Dermacentor variabilis) Most common vector
- Rocky Mountain Wood Tick (Dermacentor andersoni)
- Brown Dog Tick (Rhipicephalus sanquineus)
- Cayenne Tick (Amblyomma cajennense)
- Seasonal distribution with most infections occurring in the summer months
- Widely distributed in the US
- States with the highest incidence are Oklahoma, Nebraska, Arkansas, Tennessee and North Carolina
- Overall incidence is increasing while mortality is falling[2]
- Prior to the era of antibiotics, ~30% mortality
- Currently mortality is 3-5%
Clinical Features
- Symptoms generally begin 2-14 days after inoculation from an infected tick[3]
Early symptoms
- Non specific and highly variable
- Fever
- Nausea/Vomiting
- Abdominal pain
- Myalgias (severe calf pain)
- Headache
- Fatigue
- Conjunctivitis
Late symptoms
- Rash
- Begins as a blanching maculopapular rash that evolves to become a petechial rash
- Usually 2-5 days after fever subsides
- Starts on extremities and spreads inward (centripetally)
- Can involve palms and soles (50% of cases)
- Arthralgias
- Positive Rumpel-Leede test
- Development of petechiae at the site of blood pressure cuff and distally after compression
Complications
- Secondary to host response against infected endothelial cells
- Vasculitis
- Myocarditis
- Interstitial pneumonitis
- Encephalitis
Differential Diagnosis
- Other Tick Borne Illnesses
- Non-specific viral illness
Lower Respiratory Zoonotic Infections
- Psittacosis
- Anthrax (Bacillus anthracis)
- Brucellosis (Brucella species)
- Q fever (C. burnetti)
- Pasteurellosis (Pasteurella multocida)
- Melioidosis (Burkholderia pseudomallei)
- Rocky Mountain Spotted Fever (R. rickettsii)
- Pulmonic Plague (Yersinia pestis)
- Influenza A
- Hantavirus
Tick Borne Illnesses
- Babesiosis
- Colorado tick fever
- Ehrlichiosis
- Heartland virus
- Lyme
- Murine typhus
- Rocky mountain spotted fever
- Southern tick-associated rash illness (STARI)
- Tick paralysis
- Tularemia
Evaluation
- PCR (initially)
- Serial serologic examinations by indirect fluorescent antibody confirm the diagnosis
- Titers
Work-Up
- ECG (Myocarditis)
- Chem 7 (Hyponatremia)
- CBC (Thrombocytopenia)
Management
- Doxycycline 100 mg BID for 5-7 days[4]
- Indicated also in children at 2.2mg/kg BID
- Chloramphenicol (CAM) 50-100 mg/kg/day div Q6hr (Max dose = 4g/day)
- Preferred agent in pregnancy. May cause aplastic anemia and Grey baby syndrome, more common in near term or 3rd trimester[1]
- Consideration should be made for doxycycline over CAM in the 3rd trimester
Disposition
See Also
References
- ↑ 1.0 1.1 http://www.cdc.gov/rmsf/
- ↑ Columbia University Irving Medical Center. Rocky Mountain Spotted Fever. https://www.columbia-lyme.org/rocky-mountain-spotted-fever.
- ↑ http://www.mayoclinic.com/health/rocky-mountain-spotted-fever/DS00600
- ↑ Shandera WX, Roig IL: Viral & Rickettsial Infections, in Papadakis MA, McPhee SJ (eds): Current Medical Diagnosis and Treatment, ed 52. USA, McGraw-Hill, 2013, (Ch) 32: p 1412-1413.