CCMS Medicine Spring 2017 - 24

www.CHESTERCMS.org

LYME DISEASE CAN BE A
DIAGNOSTIC CHALLENGE
PART 2
BY MARINA MAKOUS, MD, ASSISTANT
PROFESSOR OF FAMILY MEDICINE AT
COLUMBIA UNIVERSITY DEPARTMENT
OF PSYCHIATRY

S

pring is finally here, signaling the
start of the long-awaited outdoor
play season, with opportunities
for hiking, gardening, lawn mowing,
backyard relaxation, and picnicking.
Spring is also the time of increased tick
activity, when the poppy seed-sized
nymphal ticks are questing in search of
a blood meal. These tiny creatures are
often infected with a number of bacteria,
viruses, and sometimes, parasites, which
the ticks transmit to humans while they
are attached and feeding. There are several
species of ticks, each capable of infecting
humans: deer ticks, or black-legged
ticks, prevalent in our area, can transmit
multiple infections, including Lyme
disease spirochetes, Babesia (microscopic
parasites that infect red blood cells),
Anaplasma, Powassan virus, and other
organisms. American dog ticks can
transmit various Rickettsia (for example,
Rocky Mountain Spotted Fever, which is
not limited to the Rockies, and may be
found in our area), and Tularemia; Lone
Star tick bites can cause Ehrlichiosis,
Tick-associated rash illness, and viral
encephalitis. The list of infections that
may be acquired from a tick bite is long:
think of tick bites as being stuck by a dirty
needle. In this article, I will address Lyme
disease; in the future, I will talk about
co-infections that may occur as a result
of the tick bite: Babesia, Anaplasma, and
Bartonella.

Pennsylvania has the highest number of
Lyme disease cases in the US, and Chester
county competes with the surrounding
counties for the dubious distinction of
having the most cases in our state.
The best thing is to avoid ticks
altogether: staying away from tall grass,
using DEET spray on exposed areas,
wearing light colored clothing covering
exposed skin, and wearing clothing treated
with Permethrin. You can order pretreated clothing, or alternatively, spray or
soak your outdoor wearables, including
socks, sneakers, hats, shirts and pants with
Permethrin spray (available from online or
sporting goods stores). Permethrin is not
toxic to humans (keep it away from cats).
Permethrin-treated clothing can be washed
up to 6 times; you will need to re-apply the
solution after 6 washes, or 40 days.
Careful "tick check" of all family
members (including the 4-legged ones)
after being outdoors is important. Taking
a shower within 2 hours of hiking reduces
the risk of tick attachment, too.
Despite the best precautions,
there is always a risk of tick exposure.
Environmental scientists are predicting
an unusually high population of ticks this
year. There are complex factors playing a
role in the increasing numbers and spread
of ticks. Following the previous year's
prolific acorn crops, there is substantial
rise in small rodent population. Rodents,
such as mice and squirrels, are often

24 C H E S T E R C O U N T Y M e d i c i n e | S P R I N G 2 0 1 7

infected with Lyme bacteria. When larval
ticks feed on the infected mice, they
acquire Lyme disease-causing spirochetes,
as well as other bacteria and viruses from
the mice, and then pass these on to the
next host during the subsequent blood
meal. Larger population of mice and other
rodents after a bumper crop of acorns
allows ticks to proliferate and continue to
spread.
In addition to taking care in preventing
tick exposure, it is important to recognize
Tick-Borne infections as soon as possible,
when they are most easily treatable.
Exposure to tick bites is not always
suspected or known, since the offending
tick may be missed, or found after the
transmission of the infection has occurred.
Some of the Tick-Borne infections can
be transmitted within a short time of
the tick attachment, while Lyme disease
transmission typically occurs after at least
24-36 hours of tick attachment. In some
cases, if the tick had an incomplete prior
blood meal, it may allow the spirochetes
to migrate to the tick's salivary glands,
resulting in a more rapid transmission.
Ticks can attach to any part of the
body and can be easily missed, hiding
under the hair, behind the ears, under
the arms, the groin, or behind the knees.
In the previous edition of Chester County
Medicine magazine, I described some
diagnostic challenges in interpreting Lyme
test results and establishing a diagnosis.
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Table of Contents for the Digital Edition of CCMS Medicine Spring 2017
