Parasitic Skin diseases, Arthropod

Question 1

Leishmaniasis Gen/Def: Cutaneous, Mucocutaneous, visceral

Answer 1

Flagellated, OBLIGATE, AMASTIGOTE
Transmitted: phlebotomus sand flies
-Visceral leishmaniasis: Causes FEVER, HEPATOSPLENOMEGLY, THROMBOCYTOPENIA,

Question 2

Leishmaniasis Epidemiology

Answer 2

• Reservoir: man, dog, rodents
• Usually NEW HOST (people who haven’t lived in area are the ones who get affected)
• Transmitted by sand fly taking blood meal→ inject stages into blood stream→ concentrate in skin (cool areas of body)
• Promastigote in blood stream
• AMASTIGOTE IN SKIN

Question 3

Leishmaniasis Diagnosis

Answer 3

• Ulcer at site of bite
• seen in macs on histo in skin ulcers
• AMASTIGOTE in giemsan-stained tissue
• Cutaneous and mucoid forms: No antibodies, so use PCR
• Visceral:systemic, so use serology

Question 4

Leishmaniasis Treatment

Answer 4

Prevention: cover up skin with clothing

Question 5

Larval Migrans: Hookworms (ancylostomas) General/Def

Answer 5

Lack enzymes to penetrate basement membrane of skin

Question 6

Larval Migrans: Hookworms (ancylostomas) Epidemiology

Answer 6

Definitive host: Dogs and Cats

-human is dead-in host

Question 7

Larval Migrans: Hookworms (ancylostomas) Clinical features/ transmission

Answer 7

INTENSLEY prurtic, last for months, serpiginous eruptions on feet, buttocks, abdomen

• penetrates skin on contact
• Tropical areas, travelers, walking barefoot on sand a dog pooped in

Question 8

Larval Migrans: Hookworms (ancylostomas) Diagnosis

Answer 8

-Visualizations, No Serology

Question 9

Larval Migrans: Hookworms (ancylostomas) treatment/prevention

Answer 9

Keep sandboxes covered, wear shoes

Question 10

Cercarial Dermatitis: Schistosomes General/Def

Answer 10

Aka:Swimmers itch, caused by NON-HUMAN trematodes(flukes)

Question 11

Cercarial Dermatitis: Schistosomes Epidemiology

Answer 11

BIRDS (ducks) are definitive host, humans are dead-end host.
-Contracted by swimming in contaminated water

Question 12

Cercarial Dermatitis: Schistosomes Clinical

Answer 12

Red itchy looking sores on skin-can’t fully penetrate skin-so die–causes inflammatory reaction

Question 13

Cercarial Dermatitis: Schistosomes Diagnosis

Answer 13

Clinical findings

Question 14

Cercarial Dermatitis: Schistosomes Treatment

Answer 14

Aleviate itching: Cold compress, basking soda, topical corticosteroids

Question 15

Pediculosis (lice) General/Def

Answer 15

• infestation of lice
• pediculosis capitis: “head lice”
• Classification:
• Pediculosis capitis: head lice
• Pediculosis corporis (Body lice): pediculosis vestimenti, Vagabond’s disease (thickening of skin from persistent infestation),
• Pediculosis pubis : crabs

Question 16

Pediculosis Epidemiology

Answer 16

• more common in girls: prefer long, clean hair
• common in Brazil, S. America, Central America (no one even seaks medical attention here
• can happen in every socioeconomic group. UNRELATED to hygiene (head lice), body lice IS related to hygiene
• spread by close contact, shared combs, brushes, towels, etc.

Question 17

Pediculosis Diagnosis

Answer 17

• most characteristic symptom: pruritis on head which intensifies 3-4 wks
• itching, excessive scratching can cause sores→ which can then be infected
• VECTOR: typhus, trench fever (Body lice- not head lice)
• Viewing of Nits=Lice eggs

Question 18

Pediculosis Treatment

Answer 18

• number of cases has increased
• no one product can 100% eradicate after single tx
• Chemical tx, natural products, combs, shaving, hot air, silicone-based lotions
• QUELL shampoo, short haircut

Question 19

Scabies General/Def

Answer 19

• contagious skin infection that occurs in humans and animals
• mite (Sarcoptes scabiei) BURROWS under skin (pencil marks), causing intense itching
• “Seven year itch”
• Mange in dogs/cats
• Nit: eggs, attached to hair
• Nymph: small adult
• Adult: look like tiny crabs
• Survive only a few days at room temp

Question 20

Scabies Epidemiology

Answer 20

• all ages, races, socioeconomic classes, Hygiene is IRRELEVANT
• most often in crowded, unhygienic areas
• ancient disease

Question 21

Scabies Diagnosis

Answer 21

-Definitive dx: finding scabies mites or their eggs and fecal pellets (biopsy, or dermoscopy)

Question 22

Scabies Treatment

Answer 22

• Tx similar to lice (shave and meds below)

- Be clean

Question 23

Scabies Clinical Manifestations

Answer 23

• Classic Scabies (immunocompetent): Itching, inflammation, weeping/crusty patches, WEB OF Fingers most common site of infection.
• Crusted (Norwegian) Scabies (immunocompromised): Scaly rash, thick crust, highly infectious, death from 2ndary bacterial infection,
• Atypical scabies (rare): Face, palms, scalp, soles of feet.

Question 24

Scabies Incubation period

Answer 24

Initial: 3-6 w

Re-infesteation: 3d

Question 25

Tungiasis (fleas) General/Def

Answer 25

• inflammatory skin disease caused by Tunga penetrans flea
• “sand flea”, “chigger”
• bury in skin→swell (see black hole, then subcutaneous mass)

Question 26

Tungiasis (fleas) Epidemiology

Answer 26

• found in tropics, but has spread all across world

- Lives in sand

Question 27

Tungiasis (fleas) Symptoms

Answer 27

Painless at first–itching develops–lesions–multiple lesions can make it hard to walk

Question 28

Tungiasis (fleas) treatment

Answer 28

Not covered

Question 29

Tungiasis (fleas) diagnosis

Answer 29

Identification of fleas/eggs

Question 30

Human Cutaneous Myiasis (Bot Fly) Epidemiolgy

Answer 30

• Tropics/subtropics of Africa/Americas
• Flies deposit eggs on skin, wounds, or dead tissue–hatch–larvae cut into skin
• Involves a VECTOR (mosquito)- Flies deposit eggs on mosquito–develop within mosquito–mosquito takes blood meal from human

Question 31

Human Cutaneous Myiasis (Bot Fly) Clinical Presentation

Answer 31

Painful boil-like lesions, odorous (sometimes)

Question 32

Human Cutaneous Myiasis (Bot Fly) Treatment

Answer 32

-Self limited, manual removal of larva (like squeezing a pimple)