SM 262: Bugs and Parasites

Question 1

What is the use of a KOH preparation?

Answer 1

Diagnose skin infections using skin scrapings

Detects: Tinea corporis, Tinea capitis, Tinea versicolor

Question 2

What skin infections can be detected with KOH preparations?

Answer 2

Tinea corporis, Tinea capitis, Tinea versicoloris

Question 3

What are Cimex Lectularius?

Answer 3

Bed bugs

Question 4

Where do Cimex Lectularius bites occur, and in what pattern?

Answer 4

Cimex Lectularius bites occur on the face, neck, arms, and hands

See 2-3 lesions in a row/linear of erythematous pruritic macules

Question 5

What is the Tzanck smear used for?

Answer 5

Herpesvirus

Question 6

What are Sarcoptes scabiei?

Answer 6

Superficial mites that cause Scabies

Question 7

Is Scabies contagious?

Answer 7

Yup - skin/skin contact

Question 8

How does Scabies spread?

Answer 8

Skin-skin contact

Question 9

How does Scabies present?

Answer 9

Pruritic papules, somewhat scaly, in “warm” areas of the body

Question 10

Where does Scabies present?

Answer 10

“Warm” areas like the Axilla, genital regions, under socks/watches and webbing of hands and feet

Question 11

What causes scrotal nodules?

Answer 11

Scabies unless proven otherwise

Question 12

What is a Scabies burrow?

Answer 12

A classically scaly linear burrow in the skin that may or may not always be seen

Question 13

Describe the life cycle of Scabies and how it relates to a Scabies burrow?

Answer 13

A female mite burrows into the top layers of the skin, forming a Scabies burrow, and lays eggs which are fertilized by the male

Question 14

How do you diagnose Scabies?

Answer 14

Use a Scabies prep: microscopic examination of skin scrapings to reveal the mite or eggs

Question 15

What is Norwegian scabies?

Answer 15

Scabies in immunocompromised patients, where thick scaly plaques form due to millions of Scabies mites colonizing the skin instead of just a 5-15

Question 16

Why is Norwegian scabies confused with Psoriasis?

Answer 16

Both have scales, but Norwegian scabies occurs in immunocompromised patients and the scale arises due to extensive Scabies colonization; also, there’s no redness

Question 17

How is Scabies treated?

Answer 17

Topical antiparistic meds like Permethrin for both the patient and all close contacts

Question 18

What are Crab louse?

Answer 18

Head lice

Question 19

What diseases can Crab Louse transmit?

Answer 19

Typhus, Trench Fever

Question 20

What is Erythema Migrans?

Answer 20

The classic presentation of Lyme Disease with a large bullseye lesion

Question 21

What is the cause and vector for Lyme disease?

Answer 21

Borrelia Burgdoferi on the Ixodes tick

Question 22

How does Lyme Disease present?

Answer 22

An initial erythematous macule enlarges to form a large bullseye lesion

Question 23

How can Lyme Disease be prevented?

Answer 23

Tick repellant with DEET and wear long pants