Suspecting in Patients who don’t Remember the Tick Bite
(From EMEDHome:) How then can one suspect a tick-borne illness as the cause of the typical non-specific symptoms of headache, fever, and malaise without a history of a tick bite or the presence of a characteristic rash? How does one not simply make the diagnosis of a typical viral illness? Thrombocytopenia is associated with Rocky Mountain spotted fever, ehrlichiosis, tularemia, and babesiosis. Mild elevation in hepatic transaminases is associated with RMSF, Lyme disease, ehrlichiosis, tularemia, and babesiosis. Hyponatremia is seen with RMSF and tularemia. Therefore, if you are about to diagnose a patient with a viral illness and labs were ordered in the ED, the presence of thrombocytopenia, elevated hepatic transaminases, or hyponatremia should give pause to consider the possibility of a tick-borne illness. References: (1) Massachusetts Department of Public Health. Tickborne DiseasesIn Massachusetts, a physician’s reference manual, 2nd edition: http://www.mass.gov/eohhs/
Borrelia Burgdorferi (spirochete), Ixodes Tick Bulls Eye rash-erythema migrans (usually 7-10 days post bite, but up to 30 days), though classic rash is described as red area with central clearing (15%), just the opposite can be present (32%) or homogenous erythema (53%) or vesicles/ulcerations (7%) (Ann Intern Med 136(6):421, 2002) Chronic arthritis, tropism for heart skin and CNS Stage I: Rash, malaise, arthralgias II: Meningoencephalitis, neuropathies (Bells) LP-lymphocytes, increased protein Lyme Carditis-AV BlockConduction abnormalities, especially varying degrees of atrio-ventricular (AV) block, are the most common cardiac manifestations, with complete, transient heart block occurring in about 50% of patients with cardiac involvement.53,55 Myocarditis, pericarditis, and myopericarditis also occur, and there is a single case report of pericarditis with tamponade Opthamalogic involvement III: monoarticular arthritis and possible neurologic c/o for years RX: Doxycycline 100 mg BID x 21 days Should present c low grade fever, if high, reconsider dx 1 dose of doxy post exposure has shown to reduce risk of Lyme 3.2 to .4% In one European study of 231 culture-confirmed cases of EM, data were reported on those 34 patients who specifically recalled not only the tick bite but also the duration of attachment. In nine of the 34, the duration of attachment was less than six hours, and in an additional 16 of the 34, it was less than 24 hours.(Clin Infect Dis 1996;23) Moreover, clinical LD has also been documented after as little as six hours of attachment in North America. (J Spirochet Tick-Borne Dis 1994;1:77-78) Relapsing Fever Borrelia spirochete from ticks 3 days fever, 1 week asymp, then relapse x 3-5Back to top
Francisella tularemis-hard tick Rabbits Ulcerative skin lesion c lymphadenopathy Alert lab, as it can be infectious to personnel Rx c streptomycin 1 g BID x 14 days. Typhoidal form occurs in 10-15% Ulcers and lymphadenopathy will be absent.Back to top
From deer tick Incubation of 1-60 days following bite, usually 1 week Rash present only 10% of time 2 Forms: Human Monocytic (HME) ehrlichia chaffeensis found is southern states and fever, malaise, rigors, and headache. Half will have rash. Focal liver necrosis, with spleen, bone marrow, and LN involvement. Human Granulocytic (HGE) e. equi and phagocytophila distribution similar to Lyme Similar symptoms to HME, but rarely presents with rash Leukopenia, thrombocytopenia, increased LFTs, anemia, hyponatremia Rx c doxy, should see very rapid response Also co-treat for LymeBack to top
Rocky Mountain Spotted Fever
Rickettsia Rickettsii-dog tip (dermacenter tick) April to Sept is the most common time. Fever/Rash/Tick Exposure (Can also present as nonspotted fever or it may actually be Erlichosis) Rash usually begins on the fourth day after the bite (1-15 days) erupting first on the ankles and wrists. Rash then spreads to the extremities and trunk. Starts as reddish macules that blanch with pressure, eventually advancing to petechiae/purpura. Patients will also have fever, headache, myalgias, and malaise. Abd pain and calf pain is also common. Skin-vasculitis-arms, ankles, soles. Irregular macules to maculopapular palpable generalized rash Cor-myocarditis Neuro-meningitis and HA, encephalitis and meningoencephalitis secondary to vascular injury Pulmonary involvement leads to noncardiogenic pulmonary edema, interstitial pneumonia, and adult respiratory distress syndrome (ARDS), Renal manifestations: decreased glomerular filtration rates (GFRs) and prerenal azotemia from hypovolemia. Gastrointestinal (GI) endothelial cell injury leads to abdominal pain, nausea, vomiting, and diarrhea. Many patients have guaiac positive stools. Thirty percent of patients are anemic, and death has been reported from massive GI bleeding. Fever greater than 102 degrees F – 94% of reported cases Fever within 3 days after tick bite – 66% of reported cases Headache, frequently severe – 86% of reported cases Myalgias 85% of reported cases CNS 25% of patients develop signs of encephalitis (ie, confusion, lethargy). GI some patients present with anorexia, nausea, vomiting, diarrhea, and abdominal pain. Approximately 1015% of patients have Rocky Mountain spotless fever. This more often is reported in older patients and African American patients. Spotless fever is not synonymous with mild or early illness because substantial proportions of the deaths occur in patients without a rash. Classic distribution of RMSF rash on palms and soles occurs relatively late in the course, in 43% of patients only after the fifth day of symptoms. Some reports have observed 3680% of RMSF patients without the classic distribution of rash on palms and soles. Four percent have skin necrosis or gangrene secondary to hypoperfusion. Jaundice occurs in 89% of patients. Dx: Skin Biopsy or Ab Rx: Preferred treatment is Doxy 100 mg BID PO or IV for 7 days. tetracycline,chloramphenicolBack to top
Coxiella Burnetii caused by aerosol, usually livestock, Australian slaughterhouse fever Fever and Retrobulbar headache. Myo and Pericarditis Culture negative endocarditis (Vegetations are often absent on echo) Doxycycline 200 mg loading then 100 mg BID Chronic form requires months of treatment, the acute form two weeks.Back to top
Babesia Microti in the Northeast, B. Equi in the West Protozoan-malaria like infection from ixodes tick No rash Presents very similarly to Erlichiosis but with a more predominant anemia DIC and Jaundice Lyme may be a coninfection Quinine 650 mg PO TID Clindamycin 600 mg IV Q8 or 300 mg PO Q8Back to top
Colorado Tick Fever
Viral tick-borne illness Coltivirus is a RNA virus of reoviridae family Rapid fever 3-6 days after infection. Fever can be biphasic, saddleback, with the intial fever abating and then returning 1-3 days later. May see a relative leukopeniaBack to top
Neurotoxin mediated. Ascending paralysis cured by tick removal Scrub Typhus Ricketssial from chigger mites Rx c tetracyclines The author notes that prompt suffocation of ticks with application of chemicals is unlikely, given their extremely low respiratory rate (3-15 breaths per hour). A mechanical removal technique that utilizes a straight, slow pull appears to be least likely to result in retained mouth parts.
Bites, Stings, Etc.
- Diethyltoluamide: repels biting insects, eg, mosquitoes, ticks, fleas; does not repel stinging insects, eg, bees, wasps; maximum protection with 35% to 40% concentration for adults; do not use >10% to 15% concentration on children (do not place on their hands or face); 100% DEET can be put on cotton, wool, or nylon clothing, but not skin; 100% concentration flammable, damages spandex, rayon, acetate, pigmented leather, and can dissolve plastic, vinyl, paint, and linoleum; needs to be applied only once daily; DEET in sunscreen reduces SPF by approximately 30%
- Permethrin: do not put on skin; repels and kills ticks, mosquitoes, and other arthropods; put on clothing, shoes, netting; lasts even after washing
- Items that do not work: sonic devicesit will repel your friends but it doesnt do much for insects; bug zapperskill bugs that eat mosquitoes; mosquitoes not attracted by light; citronella candleworks for 10 to 15 min; must sit right by it; not so great; Skin-So-Softof limited value, but provokes intense loyalty; works on gnats because thought it gets their feet oily so they cannot fly as well; not repellent