A 4 year old girl in day care was brought to the doctor because of several lesions on her arm. They were reddish and round, slightly raised and scaling. There were a few pinpoint pustules around the edge of the lesions. The girl had no other lesions except the ones on the arm and had no other symptoms.
Question 1 - Single Best Answer
What are three possible diagnoses that spring immediately to mind?
A) Chickenpox, Lyme disease, and impetigo
B) Rocky Mt. Spotted fever, impetigo and congenital syphilis
C) Impetigo, ringworm, and Lyme disease
D) Ringworm, Fifth disease, secondary syphilis
Question 2 - Single Best Answer
What is the causative agent of Lyme disease?
A) Treponema pallidum
B) Borrelia burgdorferi
C) Staphylococcus aureus
D) Tinea cruris
Question 3 - Single Best Answer
What is the causative agent of impetigo?
A) Staphylococcus aureus
B) Streptococcus pyogenes
C) Epidermophyton
D) It is a hypersensitivity reaction
Question 4 - Single Best Answer
What is the causative agent of ringworm?
A) Streptococcus pyogenes
B) Trichophyton
C) Tinea corporis
D) Enterobius vermicularis
Question 5 - Single Best Answer
What class of agents are Trichophyton, Microsporum, and Epidermophyton?
A) Bacteria
B) Viruses
C) Worms
D) Fungi
Question 6 - Single Best Answer
How would a case of ringworm be diagnosed?
A) Microscopic examination looking for tiny worms
B) Microscopic examination looking for hyphae
C) Growth of a swab on blood agar looking for hemolytic colonies
D) Look for serum antibodies to the fungus
Question 7 - Single Best Answer
To do a microscopic exam for fungi one should do which of the following first?
A) Gram stain
B) Treat the skin scraping with 10% KOH
C) Grow it on blood agar first
D) Grow it on SabouraudÕs agar first
E) Illuminate it with a WoodÕs lamp
A scraping of skin from the edge of the lesion on the childÕs arm was taken, treated with KOH, and examined under the microscope. Filamentous structures were seen. No flouresence with a WoodÕs lamp was seen.
Question 8 - Single Best Answer
This would lead you to diagnose
A) ringworm
B) impetigo
C) Lyme disease
D) None of the above
Question 9 - Single Best Answer
Can ringworm progress to a more serious systemic disease?
A) Yes, it can have serious sequelae, most often it infects the lungs being transported there hematogenously.
B) Only in immunocompromised patients
C) No, it is a superficial skin disease only
Question 10 - Single Best Answer
Do you know of a fungal disease that starts with a skin lesion and spreads, usually along the lymphatic glands that drain the primary site of inoculation?
A) Sporotrichosis
B) Tinea capitis
C) Histoplasmosis
D) Rocky Mountain Spotted Fever
E) Toxic Shock Syndrome
Question 11 - Single Best Answer
Which if the following is used to treat ringworm?
A) Penicillin
B) Metronidazole
C) Griseofulvin
D) Acyclovir
Question 12 - Single Best Answer
Fungi have cell walls that contain N-acetylglucosamine, so why doesnÕt penicillin work on fungi?
A) fungi are eukaryotes and penicillin only works on prokaryotes.
B) fungi have a cell membrane that contains sterols like ergosterol
C) fungi have a true nucleus
D) fungi contain mitochondria
The child was treated with topical miconazole and completely recovered.
Question 13 - Single Best Answer
What is the mechanism of action of miconazole?
A) it interacts with sterols in the cell membrane
B) it is deaminated to flourouracil and incorporated into RNA
C) it inhibits sterol biosynthesis
D) it inhibits microtubular function and acts as a mitotic poison
Question 14 - Single Best Answer
What is the mechanism of action of griseofulvin?
A) it interacts with sterols in the cell membrane
B) it is deaminated to flourouracil and incorporated into RNA
C) it inhibits sterol biosynthesis
D) it inhibits microtubular function and acts as a mitotic poison
Question 15 - Single Best Answer
How is ringworm acquired?
A) Other people
B) Animals
C) The environment; i.e., soil
D) All of the above
In summary, the child had a case of ringworm or tinea corporis. It was easily cured with a topical anti- fungal agent. Had it not been, she would have been treated with griseofulvin. She likely acquired it from another child in her day care center. Other names for fungal skin diseases are tinea capitis (scalp), tinea cruris (groin, also called jock itch), tinea pedis (feet, also called athleteÕs foot). By the way, do you know what disease killed Captain Hook? It was jock itch!