Chapter 18

Insect and Arthropod Bites and Stings

Lesson Objectives (1 of 2)

• Describe the bites of poisonous spiders, including black widow spiders, brown recluse spiders, and tarantulas, and explain how to manage such bites.

• Recognize a scorpion and its sting and know how to manage such stings.

• Assess and treat tick bites and know that some ticks can transmit Lyme disease to humans.

Lesson Objectives (2 of 2)

• Assess and manage mosquito bites.• Identify lice and no how to eradicate a lice

infestation.• Assess and treat insect stings and identify the

various types of insect repellents.

Spider Bites (1 of 8)

• Black widow spider

© photobar/ShutterStock, Inc.

Spider Bites (2 of 8)

• Black widow spider– What to look for:

• A sharp, pinprick sensation• Faint red bite marks• Muscle stiffness and cramps affecting the

bitten limb and ascending to the abdomen and thorax

• Headache, fever, chills, heavy sweating, dizziness, nausea, vomiting, and severe abdominal pain

Spider Bites (3 of 8)

• Black widow spider– What to do:

• Catch the spider for identification.• Clean the bite with soap and water.• Use an ice pack on the bite to relieve pain.• Administer pain medication orally.• Check breathing.• Seek medical attention immediately.

Spider Bites (4 of 8)

• Brown recluse spider

Courtesy of Kenneth Cramer, Monmouth College

Spider Bites (5 of 8)

• Brown recluse spider– What to look for:

• Bite with bull’s-eye appearance and a blister at the site with redness and swelling

• Local pain• Fever, weakness, vomiting, joint pain, and a

rash

Spider Bites (6 of 8)

• Brown recluse spider– What to do:

• Catch or kill the spider for identification.• Clean the bite with soap and water. • Use an ice pack on the bite to relieve pain.• Administer pain medication orally.• Seek medical attention promptly if large

areas of inflammation develop.

Spider Bites (7 of 8)

• Tarantula

© photobar/ShutterStock, Inc.

Spider Bites (8 of 8)

• Tarantula– What to do:

• Clean the bite with soap and water. • Relive pain with an ice pack. • Evacuate if the species is known to

be dangerous.

Scorpion Stings (1 of 4)

© Kirubeshwaran/ShutterStock, Inc.

Scorpion Stings (2 of 4)

• What to look for:– Instant local pain and burning– Difficulty swallowing– Slurred speech– Numbness and tingling

Scorpion Stings (3 of 4)

• What to look for:– Occasional paralysis– Muscle spasms– Breathing difficulties– Jerking and twitching

Scorpion Stings (4 of 4)

• What to do:– Check breathing.– Clean the bite with soap and water.– Apply an ice pack to relieve pain.– Evacuate as soon as possible.

Centipede Bites (1 of 2)

• Centipedes have small fangs and venom glands.• Burning pain, swelling, and redness can last up

to 3 weeks.

Centipede Bites (2 of 2)

• What to do:– Most bites will get better without treatment.– Administer antihistamines by mouth.– Apply hydrocortisone on the bite.

Tick Bites (1 of 7)

© Joao Estevao A. Freitas (jefras/ShutterStock, Inc.

Tick Bites (2 of 7)

• What to do:– Difficult to remove– Improper or partial removal can lead to local

infection.– Use tweezers or a tick removal device to grab the

tick close the skin and pull steadily; or lift slightly upward, and then pull parallel to the skin.

– If head remains embedded, remove with a needle.

Tick Bites (3 of 7)

• What to do:– Wash the bite with soap and water. – Apply an ice pack for pain.– Watch for signs of local infection.– Watch for symptoms of tick-borne illness.– Seek medical attention if symptoms appear.

Tick Bites (4 of 7)

• Lyme disease– A potentially serious tick-borne infection– Affects the joints, skin, heart, and nervous

system– Transported by ticks from deer and mice

to humans

Tick Bites (5 of 7)

• Lyme disease– What to look for: Early stages

• Distinctive rash• Fatigue• Fever• Chills• Weakness• Headache• Stiff neck• Muscle or joint pain

Tick Bites (6 of 7)

• Lyme disease– What to look for: Later stages

• One-sided paralysis• Arthritis• Meningitis• Nerve damage• Heart damage

Tick Bites (7 of 7)

• Lyme disease– What to do:

• If symptoms appear within a month of a tick bite, consult a doctor.

• Antibiotic treatment is usually curative.

Mosquito Bites

• Mosquitoes carry many diseases.• Use an effective repellent and mosquito netting.

Lice (1 of 2)

© Phototake, Inc./Alamy Images

Lice (2 of 2)

• What to do:– Treat with lice shampoo or lotion containing

permethrin, pyrethrins with piperonyl butoxide, or lindane.

– Wash clothes, sleeping bags, pillow cases, or other bedding in soap and hot water.

– Do not share clothes or hairbrushes.

Insect Stings (1 of 7)

• Honeybee• Bumblebee• Yellow jacket• Wasp• Fire ant

Insect Stings (2 of 7)

• What to look for:– Stinger may be visible.– The sooner symptoms develop, the more

serious the reaction.

Insect Stings (3 of 7)

• What to look for:– Local reactions

• Brief pain• Redness• Swelling• Itching• Heat

Insect Stings (4 of 7)

• What to look for:– Generalized reactions

• Diffuse skin redness• Hives• Swelling of lips or tongue• Wheezing• Abdominal cramps• Diarrhea

Insect Stings (5 of 7)

• What to look for:– Life-threatening reactions:

• Inability to breath due to swelling of the air passages and throat

• Bluish or gray skin color• Seizures• Unconsciousness

Insect Stings (6 of 7)

• What to do:– Scrape the stinger and venom sac off the skin.– Wash the sting with soap and water.– Apply cold to the site for 15 to 20 minutes.– Give a mild analgesic.– Use hydrocortisone and antihistamines to

reduce local symptoms.

Insect Stings (7 of 7)

• What to do:– Use a paste of baking soda and water to

absorb venom and relieve pain.– Observe for at least 60 minutes for serious

allergic reaction.– If hives or redness and swelling occur with

difficulty breathing, administer epinephrine.

Insect Repellents

• Natural repellents (citronella and lemon eucalyptus)• Synthetic repellents (DEET and dimethylphthalate)• Insecticides (permethrin, deltamethrin, and

alphamethrin)