Spirochetal Disease

Spirochetal Disease-

-Lyme Disease-

-Lyme disease is a tick borne illness caused by Borrelia burgdorferi

-Lyme disease was first described as "Lyme Arthritis" which was a cluster of children who developed juvenile rheumatoid arthritis is a community in Connecticut

-Three Phases of Lyme Disease:
1.  Early Localized Disease:  characterized by appearance of skin lesion (Erythema Migrans), with or without constitutional symptoms

2.  Early Disseminated Disease:  characterized by multiple erythema migrans lesions and/or neurologic and cardiac findings that can occur weeks to months after inoculation.  Many patients will have no history prior early localized disease

3.  Late Lyme Disease:  involves intermittent or persistent arthritis involving one or a few larger joints.  The knee is most commonly affected.  May have other neurologic problems such as mild encephalopathy or polyneuropathy.  May develop months to years after initial inoculation of the organism.

-Arthritis maybe the only manifestation of the disease

-Other symptoms with Lyme disease include:  fatigue, headache, anorexia, neck stiffness, fever, regional lymphadenopathy, arthralgias, and myalgias

-Typically will not have respiratory or GI symptoms.  Should consider lyme disease if not present

-Serologic testing for antibodies to B. burgdorferi should be used as an adjunct for diagnosis.  This just means that they have the antibodies and may have been exposed.

-In terms of Lyme disease antibiotic prophylaxis following a tick bite, amoxicillin is ineffective and doxycycline is effective

-Oral doxycycline, amoxicillin and cefuroxime have equal efficacy in treating lyme disease

-Most treatment regimens should be 21 days in length


-Rocky Mountain Spotted Fever-

-Rocky Mountain Spotted Fever (RMSF) is a rickettsial disease that is potentially lethal

-RMSF is a tick born disease

-RMSF can vary from mild disease to fulminant disease

-RMSF is caused by the organism Rickettsia rickettsii, which is a gram negative bacteria that is obligate

-Rickettsial infection leads to direct vascular injury which caused prostaglandin production and contributes to increased vascular permeability

-Rickettsial infection then can lead to activation of clotting factors, but true DIC is rare

-Hyponatremia comes from increased ADH from hypovolemia and decreased tissue perfusion

-Rickettsial infections can lead to interstitial pneumonitis, myocarditis, and encephalitis

-RSMF occurs in the US, Canada, Mexico, Central America and parts of South America

-The highest incidence of RMSF is in children less than 10, but has been seen in persons aged as high as 64

-Clinical manifestations of RMSF include:  fever, headache, malaise, myalgias, and joint pain with rash.  The headache is often the worst symptom and fever is present in almost all cases

-Physical exam can reveal the rash, pedal edema, confusion, conjunctival erythema, and retinal abnormalities.  Neck stiffness may be present with CNS involvement

-The diagnosis of RMSF is initially made clinically on symptoms and the right area of the world.  There is no reliable diagnostic test in the early phases of the disease when therapy should be started

-Clinical confirmation must be confirmed by skin biopsy or through serologic testing.  Indirect fluorescent antibody test is the standard method for serology for RMSF

-Doxycycline is the drug of choice for both adults in children except pregnant women for RMSF

-Chloramphenicol is the preferred treatment for most pregnant women

-Treatment should be continued for at least 72 hours after the patient does not have a fever


-Syphillis-

-Syphillis is an infection caused by the bacteria Treponema Pallidum

-Early syphillis has 3 stages primary, secondary, and early latent syphillis

-These occur usually within a year of acquiring the infection

-Latent syphillis is characterized by an asymptomatic infection with a normal physical exam and positive serology

-Studies have shown that the majority of case of syphillis occur in homosexual men

-Infection of Treponema Pallidum occurs only via direct contact with the infected lesion during sexual intercourse

-The early lesions of primary and secondary syphillis are very contagious.  Up to one third of patients exposed to these lesions will acquire the disease

-Syphillis can be also spread through touching or kissing a person who have active lesions on the lips, oral cavity, breast or genitals

-Primary syphillis presents usually as a painless lesion at the site of inoculation about 2-3 weeks of incubation.

-The typical chancre is 1-2 cm ulcer that is raised with an indurated margin.  These are usually on the genitalia.

-Chancre can occur at other sites of inoculation including vagina, posterior pharynx, and anus

-Chancres typically heal within 3-6 weeks without treatment

-Secondary syphillis occurs weeks to a few months later and rash can take any form except vesicular lesions.

-The classic rash of secondary syphillis is diffuse, symmetric macular or papular eruption on the extremities including the palms and soles of feet.

-Systemic symptoms of secondary syphillis can include fever, headache, anorexia, sore throat, myalgias, and weight loss.  Lymphadenopathy can sometimes be appreciated in the posterior cervical, axillary, femoral and inguinal regions

-Other complications of secondary syphillis include alopecia, hepatitis, GI ulcerations, synovitis, albuminuria, invasion of CSF, and posterior uveitis

-Neurosyphillis is an infection in the CNS by Treponema Pallidum

-The chancre of primary syphillis is best diagnosed with dark field microscopy

-Secondary syphillis is best diagnosed by serology (non Treponemal VDRL, RPR, and TURST  tests)
(Treponemal tests include FTA-ABS, MHA-TP, TP-TA, and TP-EIA)

-Penicillin G 2.4 million units is the treatment of choice for all stages of syphillis