• “Itch mite” caused by Sarcoptes Scabiei
• Transimitted by skin-to-skin  contact, or from clothing or bedding infested with the mite
• often seen in close living quarters (nursing homes, army barracks, overcrowded housing)
• Female mite burrows into the skin and deposits eggs and feces into skin
• Eggs hatch within 3-4 days
• Hypersensitivity causes very itchness from the actual mite

• Sensitization usually occurs after 1 month
• Have to take a hx of what they did 4-6 weeks ago; ask if anyone else is itching at home
• Intense pruritus with minimal skin findings
• Find a lot of scratch marks
• Usually found at finger webs, wrist creases, axilla, lower abdomen, groin, feet
• Often burrows are only found on the feet because they have been scratched off in other locations
• Pruritus most severe at night
• Itching so much not sleeping at night time
• Scratching may cause secondary infection.
• Norwegian (keratotic) scabies – seen frequently in elderly and others that are immunocompromised
• Associated with high amounts of mites
• Evidence of thick scale
• Will affect majority of body (even scalp and face)

• Ask patient if they have severe itching especially at night
• Any recent vacations, hotel stays, sexual partners etc.
• Scabies prep
• Scrape off a burrow.  Mite, ova and feces can be seen under microscope.

• Permethrin 5%
• • Applied HS.  Rinse in AM.  Repeat in 1 week.
• Topical corticosteroids for symptoms and any associated dermatitis
• Ivermectin
• • Oral medication
• All clothing, bedding, towels must be washed
• Fingernails trimmed
• Family and sexual partners should be treated

• Lice infestations in humans are caused by ectoparasites
• • Head lice – pediculosis humanus var. capitis
  • Body lice – pediculosis humanus corporis
  • Pubic lice – Phthirus pubis

Lice: Pediculosis Capitis 

Clinical Manifestations 

• Intense pruritus of the scalp
• Small, white, oval-shaped capsules firmly attach to hair shaft close to hair follicle
• Are easiest to see above the ears and at the nape of the neck
• Hair appears lusterless, very dry and not as shiny
• Mite has an elongated body that conforms to hair shaft.

Lice: Pediculosis Capitis 

Treatment

• Must destruct lice and ova
• Permethrin 5% or 1% applied and washed off after 10 minutes.  Repeat in 7 days
• Malathion (Ovide) – not in kids < 6 months
• Remaining nits must be removed by fine toothed comb

Lice: Pediculosis Corporis 

• Seldom found on body because the insect comes onto skin only to feed
• Look under belts, collars, or bedding
• Intense pruritus and scratching may  result in deep excoriations
• Papular urticaria at site of mite bite
• Treat by disposing infested clothing.

• May be acquired by sexual transmission or from shared bedding
• Seen on or around genitals, lower abdomen, eyelashes
• See a yellowish brown or gray “speck” on the skin
• Pruritus
• Will see nits on hair and lice on skin
• Treatment
• • Permethrin cream
  • Treat sexual partners
  • Bedding and clothing need to be decontaminated.
  • Eyelashes should be coated with petroleum jelly for 8 days.

• Black Widow Spider 
• Brown Recluse Spider 

• Has a red hourglass shape marking on abdomen
• Only females are capable of envenomation of the neurotoxin
• Symptoms – Increase in severity up to 24 hours
• • Abdominal pain
  • Hypertension
  • Muscle complaints
  • Irritability or agitation
  • Mild erythema at bite site
  • May see red-brown fang marks
  • Nodes draining bite site may be painful and enlarged
• In the young and elderly, paralysis, shock  and convulsions may occur.   Death is rare.

• Ice - to restrict spread of venom 
• Antivenom ( IM or IV) 
• Ca+ gluconate for abdomen ( muscle relaxant) 

• May cause necrotic arachnidism
• Spider is yellow, tan or brown in color and can be identified by a dark-brown, violin shaped cephalothorax
• Symptoms
• • Localized pain, burning and stinging 6-8 hours after bite, as vasospasm causes local tissue ischemia
  • May show localized hive-like reaction
  • A cyanotic color, followed by expanding necrosis of the skin develops within days

• Supportive care
• Ice, cold wet dressings, elevation, analgesics
• Local wound and ulcer care, early excision
• Dapsone (may be helpful in preventing severe necrosis)