of the case
D.... presented with an “itch” in the right cubital fossa.
24 hours old
He applied betadine
No history of tick bite reactions.
Surrounding 1 cm diameter mild erythema
Afebrile and clinically well
Immediate removal using forceps - deep in wound
Appropriate clinical care after removal depends upon timing
100mg bd for 3 weeks or
amoxicillin for younger children or where the former can not be used
D.... was instructed to return if any local inflammation developed or if he felt unwell in anyway.
He returned 48 hours later with
The lesion had the clinical appearances of early erythema migrans EM. Serology at this early point for Lyme disease would be negative. At this juncture it was not known by the author that a skin biopsy at the outer edge of induration would be helpful in proving the assumed diagnosis.
Treatment was commenced with doxycycline 100 mg bd for 3 weeks. He was reviewed 5 days later and showed excellent response.
Lyme Disease has 3 clinical phases (1)
include fever, fatigue, headaches, myalgia, arthralgia and lymphadenopathy,
usually within 2-3 weeks of infection. Erythema migrans (EM) appears 3-30 days
after the bite of an infected tick, usually at the site of inoculation. The
initial lesion is a red maculo-papular lesion greater than 5cm in diameter,
rarely painful and expands and may reach more than 50cm in diameter, with
central clearing and a well-defined, circinate border ("bulls-eye").
are non-specific and occur weeks or months after the tick bite: carditis,
chronic meningitis, mononeuritis (eg Bell's palsy) and conjunctivitis,
arthralgia and myalgia.
occur months or years after exposure. The most typical feature in North American
is an erosive arthritis of large joints, particularly the knees. In European
patients a chronic skin manifestation, acrodermatitis chronica atrophicans (ACA)
Isolation of the causative
organism from a punch biopsy taken at the edge of the EM lesion is successful in
up to 80% of cases but it may be up to 8 weeks before spirochaetes can be
detected. Polymerase chain reaction (PCR) has the advantage of greater
sensitivity and speed (result in 24 hours). (1) Isolation and/or PCR should be
attempted upon presentation of a patient with an EM lesion. (1)
Serology in phase 2 and 3 can
be positive and includes (1)
antibody test (IFAT)
Enzyme linked immunosorbent
Western immunoblot (WB).
False positive results occur
due to cross reactions with other bacteria,viruses and
autoimmune diseases. At the Sixth International Congress on Lyme
Borreliosis a standardised interpretation of WB results was accepted. An IgG
immunoblot is considered positive if 5 of the following 10 bands are present:
18, 21, 28, 30, 39, 41, 45, 58, 66 and 93kDa. Patients with late stage disease
will show 10 or more bands on a WB. (1)
In this community any
reaction to a tick bite after 48 hours, if the tick has been removed, is likely
to be QTT or possibly Borrelia burgdorferi infection
Such conditions are best
treated with doxycycline at this time to prevent latent clinical disease.
Amoxicillin may be used in younger children if erythema migrans has occurred but
will not be helpful for QTT
The current status of Lyme disease in xxxxxxxxxxxxx see below at references. (1) Until this issue is resolved suspicion is required treating tick bite and where the clinical evidence justifies, appropriate therapy is required
We have found that in this
community the clinical condition of erythema migrans can be judged by size and
attempts to prove the causative organism Borrelia burgdorferi by skin biopsy
should be undertaken. A concerted effort by Australian practitioners in this
regard will help towards the task of demystifying Lyme disease in this country.
Attempts to treat a minor
localised erythema of less than 48 hours duration can mask the development of
more serious sequelae (3)
Treatment interval needs to
be updated. Current northern hemisphere opinion for EM has been 2-3 weeks (3).
Warmser et al (4) found no difference in follow up after 10 or 20 days
doxycycline at 100mg bd in a double blind crossover randomised trial
D. and Gilbert, G.L. (1994). Lyme Disease in Australia? Western immunoblots not
the final answer. Annual Scientific Meeting Australian Society of Microbiology,
GP, Nadelman RB, Dattwyler RJ, Dennis DT, Shapiro ED, Steere AC, et al. Practice
guidelines for the treatment of Lyme disease.
The Infectious Diseases Society of America. [PMID: 10982743] Clin Infect
Dis. 2000;31(suppl 1):1-14
Ramathan et al. Duration of antibiotic therapy for early Lyme disease – a
randomised double blind trial placebo controlled trial.
Ann Intern Med 2003: 138:697-704. 6 may 2003
Further suggested reading
Lyme disease in Australia
DOGGETT, S.L., RUSSELL, R.C.,
Munro, R., Dickeson, D., Ellis, J. Avery, D., Hunt, C.L., Simmonds, J. and
Trivett, N. (1994). Lyme disease - the search for the causative agent in
southeastern Australia. Arbovirus Research in Australia. Arbovirus Research in
Australia, 6: 313-315.
Hudson, B.J., Barry, R.D.,
Shafren, D.R., Wills, M.C., Caves, S.F. and Lennox, V.A. (1994). Does Lyme
borreliosis exist in Australia? Journal of Spirochaetal and Tick-Borne Disease;
Piesman, J. and Stone B.F.
(1991). Vector competence of the Australian paralysis tick, Ixodes holocyclus,
for the Lyme disease spirochaete Borrelia burgdorferi. International Journal
Parasitology, 21: 109-11.
RUSSELL, R.C., DOGGETT, S.L.,
Munro, R., Ellis, J., Avery, D., Hunt, C., and Dickeson, D. (1994). Lyme
disease: A search for a causative agent in ticks in southeastern Australia.
Epidemiology and Infection, 112: 375-384.
RUSSELL, R.C. (1995). ?Lyme
disease in Australia - still to be proven! Emerging Infectious Diseases, 1:
Wills, M.C. and Barry, R.D.
(1991). Detecting the cause of Lyme disease in Australia [letter]. Medical
Journal of Australia, 155: 275.