Infestations / Bites

Question 1

Scabies (Sarcoptes scabiei)

Answer 1

Intense Pruitus, contagious, found on body folds, wrist, and web spaces.Skin Findings:Eczematous reaction pattern with excoriation. Burrows. 1-2mm postules infants.Testing:mineral oil / KOHRx: Lindane,Elimite, Ivermectin, Antihistamine.

Question 2

Lice“Pediculosis”

Answer 2

• An infestation that may affect scalp hair, pubic hair, body hair. Hihgly contagious with direct body contact. Black dot at base of hair
• Head louse (Pediculus humanus capitis)-school aged children,nits present.
• Body Louse (Pediculus Humanis corporis)-stay on clothes, poor hygeine
• Pubic Louse (Phthirus pubis)-STD,Maybe found in genital area, eyebrow, eyelashes, axilla, short occipital scalp hairRx:Permetherin rinse (NIX/Elimite), Ivermectin, vaseline,lindane,Shave, repaet topical treatments in 1 week.

Question 3

Flea Bites

Answer 3

• A pruritic eruption found on the legs, papules
• Vessicles / bullae may be present
• Self limiting, may subside in 1-2 weeksRx:Topical steroids, Antibioticvs for infected lesions, eradicate fleas.

Question 4

Bed Bugs

Answer 4

• 5-7 mm in length & wingless
• normally feed at night
• The eggs hatch in 10 days. The nymph stage lasts 6 weeks, undergoing 5 moltsRx:Topical steroids, antihistamines, extermination

Question 5

Rocky Mountain Spotted Fever

Answer 5

• Potentially lethal disease characterized by an acute onset of ( fever, headache, myalgia, vomitting, petechial rash)
• Transmision through american dog tick / rocky mountain wood tick.
• 7 day incubation period Rash - 80% of cases have rash 3-4 days after devloping fever /chills. Discrete macules, blanches with pressure, petechial 2-4 days. Starts on wrist / anckles -> palms / soles ->generalized. Diffuse vasculitus with gangrene may occur May involve GI, Resp & CNS Fever subsides 2-3 weeks Rash leaves PIH Mortality rate 20% untreated& 4% treated Labs:Indirect immunoflouresence, increased LFT’s, low NA, low platelets, leukocytes (wnl or low)Rx:Doxycycline 100 mg bid x710d. Chloramphenicol 50mg/kg/day

Question 6

Lyme Disease

Answer 6

• Most common vector-borne infectious disease in the US Causative agent Borrelia Burgdorferi, a spirochete.via Ixodes Scapularis deer tickOnset:3-21 days post bite, round expanding skin lesion (erythema Migrans), fevel, malaise, headache, stiff neck, myalgia/arthralgia.Skin FIndings:Erythematous papule→enlarging ring→central erythema fades→normal or light blue surface. Blanching with compression. Lesions fade 3-4 weeks.Associated with arthritic, cardiac & neurological symptomsRx:Prevention,Doxy 100mg bid x 21 days

Question 7

Animal Bites

Answer 7

• m/c/c Pasteurella Multocida
• Rabies prophylaxis (immune globulin @site and distal)
• Tetanus
• Do not close puncture wounds
• cat puntures more dangerous than dog lacerationsRx:Augmentin 875mg bid x 10d, Irrigate well.

Question 8

Brown Recluse(Loxosceles Reclusa)

Answer 8

Bites -

• May be painful or painless,localized pain,burning.
• Systemic manifestations may be present (uncommon) 12-24h after bite
• Rash
• Necrosis - 10% of cases
• Sphingomyelinase-D – toxin responsibleRx:Supportive (rest, ice, analgeisic,), Wound care, antibiotics / tetanus, Dapsone, oral steroids, Hyperbaric chamber.