Description: Tick on end of pencilTicks are in the same family as spiders and hence share some characteristics with them (e.g. like spiders, Ticks have eight legs).  They are parasites living on the blood of other animals a practice which makes them vectors (carriers) of several diseases including Lyme Disease and Rocky Mountain Spotted Fever.  The tick bite itself  does not cause diseases but rather the secretions or organisms in the tick’s saliva that is transmitted into the hosts’ body.

Ticks have a round body from size of pinhead to 2.5 centimeters, eight legs and sucking mouth parts on a head that is projected forward from the body. The tick’s body appearance can greatly differ if the tick is engorged with blood.  There are two types of ticks – a “hard tick”, one with a hard outer shell covering their body and the “soft tick” one with a softer body mass.  Their body is divided into two sections – a section that contains the head and mouthparts and a section that contains the legs and digestive tract.  There are thousands species worldwide.

Tick on blade of grassTicks extract blood from their host by cutting a hole in the host using their mouthparts and inserting a appendage through which they suck the blood.  Using barbs in their mouthparts or a cement like secretion, ticks remain attached to the host while the blood is being withdrawn.  They may excrete a substance that slightly deadens the bite area (the host often never realizes the tick is attached to them) and a blood thinner that makes extraction of the blood more efficient.

Removing a tick: To remove an attached tick, use tweezers to grasp the tick as close to the skin as possible.  Do not twist nor yank but pull steadily.  Jerking can break the tick leaving mouthparts behind or cause the tick to regurgitate potentially infectious fluids.  After removal, the site of the bite should have a small indention where the tick’s head and mouthparts were embedded.  After removing the tick, clean and disinfect the bite area. If possible, keep the tick’s body in case complications from the bite arise later (doctors can use the tick’s body in their diagnosis and treatment plan).

Do not use a hot match head to force the tick to disengage their bite.  Also, do not apply paint, nail polish, petroleum jelly or gasoline which may cause additional injuries and can cause the tick to produce more pathogen-containing secretions into the bite site.

Symptoms of a tick bite: Tick on blade of grassDisease infection usually occurs at the end of the tick’s meal as they become full of blood.  Tick bites are usually painless and some are so small they are nearly undetectable. Sometimes the neurotoxin that they excrete (to numb the bite area) can cause muscle weakness. Some people may notice redness, burning, or itching at the bite area. However, the majority of tick bites result in no symptoms whatsoever.

After a tick bite, symptoms may arise hours, days, or weeks later.  These symptoms can include fever, numbness, weakness, confusion, rash, swelling in the joints, shortness of breath, nausea, and vomiting.  Some symptoms may be specific to the type of disease that was transmitted from the tick during the bite.  Diagnosis of a resulting disease can be difficult.  Blood tests for diseases can be used but some positive blood results will not appear for weeks after the symptoms begin.

Two tick related infections include Rocky Mountain Spotted Fever and Lyme Disease, both of which produce recognizable, tell-tale signs of the infection.

Rocky Mountain Spotted Fever: Rash on arm of Rocky Mountain Spotted Fever patientThis is the most lethal and commonly reported tick-related disease.  Initial signs of the disease include the sudden onset of fever, headache, and muscle pain.  Early symptoms may also include nausea, vomiting, and lack of appetite.  These symptoms are followed by a rash that typically begins at the extremities (from wrists and ankles to arms and legs) and progresses toward the body.  This rash, which appears as small, pink, non-itchy spots on the extremities, appears 2-5 days after the onset of fever.  When pressure is applied to the spots they become pale.  For many infected persons, after 5-7 days, the rash becomes red and spotted.  In some victims, the disease never produces a rash of any kind.

Treatment for Rocky Mountain Spotted Fever includes antibiotics.

Lyme Disease: Characteristic circular rash present in Lyme Disease patientLyme Disease is probably the most common tick-borne disease.  Early symptoms typically appear about 1-2 weeks after the bite but can occur sooner (days) or much later (months to years).  Symptoms typically occur from May to September (because of the tick’s growth stage).  Early symptoms include fever, headache, fatigue, and depression.  Other symptoms may include pain in muscles and joints, heart palpitations, and dizziness.  Rare symptoms include memory loss, trouble sleeping, mood changes, loss of muscle tone on one or both sides of the face as well as neck stiffness and sensitivity to light.

The early symptoms are typically followed by a characteristic outwardly expanding circular skin rash at the site of the tick bite.  This circular rash, which occurs in 80% of the infected victims, contains a inner dark red spot with a center that is thicker and firmer followed by a clear circular area that is followed by a red, outer ring.  This pattern gives it the appearance of a bullseye.   Later, these circular rashes may begin to appear at other sites on the body.

If left untreated, more serious symptoms can occur and treatment becomes much more difficult.  Diagnosis is usually based on characteristic symptoms and a history of possible exposure to infected ticks.  Antibiotics such as doxycycline are used in treatment.  Some believe that antifungal drugs such as Diflucan or Trican can treat infections if used early.

Avoiding Tick Bites: Several ticks under magnificationThere are several things you can do to avoid tick bites.  A DEET insect repellent applied to the skin is effective as is a Permethrin product applied to the clothing, tents, and chairs.  Wearing light colored clothing makes it easier to see ticks and long pants and hiking boots with pants tucked into the leg keep ticks from getting to the body.

Ticks prefer high vegetation so travelling on a trail will keep you out of their environment.  A daily check for attached ticks is helpful.  Upon returning to civilization, run clothes through a high-heat clothes dryer to kill ticks (a hot water washing is often not effective in killing ticks).

Habitat: Mainly in forests and grasslands. Also in urban areas and farmlands.

Distribution: Worldwide but they tend to flourish in environments that offer warm, humid climates.

Engorged soft tick

Hard Tick with shelled exoskeleton

Difference in tick appearance when engorged with blood

Soft ticks

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