Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MBBS 4 Dermatology > Infestations > Flashcards

Infestations Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

Types of infestations?

A
  1. Scabies
  2. Tungiasis
  3. Creeping eruption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is scabies?

A

Very infectious disease caused by mite sarcoptes scabei var hominis
- Human only known reservoir of the mite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Epidemiology of scabies?

A
  • Worldwide infestation, affects all ages, races and socio-economic classes
  • High prevalence in children, and sexually active people
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is scabies usually seen?

A
  1. overcrowded places (prison, schools, refugee camps)
  2. delayed treatment of primary cases increase spread.
    - Role of hygiene not clear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain how scabies is a public health problem?

A
  • Designated a neglected tropical disease in 2017
  • Increase awareness and elimination efforts
  • Over 130 million people affected by scabies at any point in time globally
  • Up to 10 % of all children in tropical developed world suffer from scabies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Transmission of scabies?

A

Transmitted directly by close contact, sexual or otherwise; and indirectly via formites.
1. infested people that do not have symptoms can spread
2. Prolonged contact required
3. In adults, spread from sexual contact frequent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the survival of scabies?

A
  • Female mites can survive up to 55-67 hrs off the host in tropical climates.
  • Eggs in cooler environment can survive up to 10 days.
  • Patients with crusted scabies shed mites freely and a high source of infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pathogenesis of scabies?

A
  1. Complete life cycle of the mite in human epidermis.
  2. A female mite lays eggs which mature in 10 days.
    - Usually only a few mites 8-15 live on an infested host.
    - Thousands in crusted scabies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When do symptoms of scabies show?

A

Symptoms due to delayed hypersensitivity reaction to the mite and/or eggs.
1. First infection: symptoms take a minimum of 3-4 weeks
2. Re-infection: 1 – 2 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Clinical features of scabies - history?

A
  1. Intense pruritus, worse at night.
  2. Close personal contacts/household members may report itch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Clinical features of scabies - findings?

A

Papules, pustules, burrows.
Areas:
- hands (interdigital, fingers), fingers, wrists, elbows, shoulders, genital area, lower legs, ankles, scrotum, breasts.
- Other signs: excoriations, secondary super-infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are crusted scabies?

A
  • found in immuno-compromised people and those with decreased sensory function e.g. leprosy, paraplegia.
  • These crusted infections are caused by a superinfection with thousands of mites, and such patients are very contagious.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are clinical features of crusted scabies?

A

dry scales and crusts , most marked over prominences dorsum of the fingers, wrists, and ears.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are post scabitiec nodules?

A

itchy larger, nodules seen after scabies treatment due to hypersensitivity to dead mites
- Common in genital area, and lack burrows.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Complication of scabies?

A
  1. Secondary infection with grp A streptococci which has lead to cases of post streptococcal gromerulonephritis, rheumatic fever.
  2. Stigma and discrimination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Management of scabies?

A
  1. Treat all contacts and household members as the patient regardless of symptoms.
  2. Identify and immediately treat crusted scabies patients.
  3. Patients should be given specific instruction about use of the drugs.
  4. All clothing used in the past week be stored unused for at least 10 dys
    - Washing in hot water, and ironing clothes, though commonly advised, may be impractical, and little evidence available.
17
Q

Medical treatment of scabies?

A

Benzyl Benzoate Emulsion (BBE)
- Cheap and quite effective
- Apply overnight for 3 consecutive days, then repeat cycle after 7 days (i.e 6 nights in 2 wks)
- Irritating. For the first 30min – 1 hr
- Dilute the 25 % emulsion in children and infants, even though this reduces efficacy.

18
Q

Treatment of crusted scabies?

A
  1. Oral ivermectin 200μg/kg on day 1, repeat day 14.
  2. Salicylic acid 10 % and emmollients to shed scales.
19
Q

What is tungiasis?

A
  • Caused by flea, Tunga penetrans.
  • An impregnated female flea burrows into skin and lodges in the epidermis and engorges.
  • Creates a lesion that resembles an abscess with a central punctum.
  • Due limited jumping ability, commonly affected areas are feet.
20
Q

Clinical features of tungiasis?

A

Pain or itch as the flea burrows.
Sites: soles, toes, toe webs, thighs, perineum, genitalia.

21
Q

Complications of tungiasis?

A
  1. ulceration
  2. infection (including tetanus)
  3. lymphangitis.T
22
Q

Treatment of tungiasis?

A
  1. spontaneous recovery may occur
  2. Manual removal of flea with sterile needle
  3. If numerous, topical ivermectin, vaseline, paraffin may facilitate killing of mite, but the actual mites will eventually need manual removal .
  4. Consider tetanus prophylaxis
23
Q

What is creeping eruption?

A
  • Caused by larvae of hookworms of cats and dogs.
  • Eggs are deposited in the soil, from where the larvae hatch and accidentally enter human host via exposed areas (buttocks, feet, hands).
  • Man being wrong host, the larvae will wander around seeking blood vessel to enter, but with no proper adherence molecules, dies.
23
Q

Prevention of tungiasis?

A

Prevention: wear shoes, avoid sitting, walking bare in beaches in endemic areas.

24
Q

Clinical feature of creeping eruption?

A

itchy, erratic winding trail
- May be obscured by excoriations.

25
Q

Treatment of creeping eruption?

A

Disease usually self-limited , but the itch and infection necessitate treatment
1. Albendazole 400mg BD for 5 days
2. Thiobendazole cream 15 % 4x daily till 2 days after track disappears.
3. Oral Ivermectin 12 mg single dose.
4. Cryosurgery: freeze 1 cm ahead of visible trail to target the head.

26
Q

What is papular urticaria?

A
  • mostly on the extremities of children,
  • immune reaction due to insect bites, fleas, bedbugs.
  • May take several weeks to resolve
  • Very itchy
27
Q

Clinical features of papular urticaria?

A
  1. urticarial, erythematous papules, with predilection of extremeties.
  2. May be generalised in severe disease, but lack burrows, interweb papules
  3. Lack history of involvement in family members
28
Q

Management of papular urticaria?

A

Management:
1. Prevent bites
2. Protective wear during susceptible times, treat house/environments known to be infested
3. Medical
4. Topical steroids
5. Treat any associated superinfection
6. Antihistamines for itch

MBBS 4 Dermatology (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions