Infections of Skin

Topics in this chapter

• Bacterial Skin Infections
• Fungal Skin Infections
• Parasitic Skin Infections
• Viral Skin Infections
• Atypical Mycobacterial Infections
• Cutaneous Manifestations and Mimics

Practice questions

1. Question 1Q-7EF43F

   A 35-year-old immunocompetent male presents with a well-demarcated, bright red, tender plaque on his right cheek with a distinct raised border, accompanied by fever and chills. Which of the following is the most common causative organism?

   1. A.Staphylococcus aureus
   2. B.Streptococcus pyogenes
   3. C.Pseudomonas aeruginosa
   4. D.Propionibacterium acnes
   See the answer and solution
2. Question 2Q-BF5754

   A 24-year-old man presents with multiple intensely pruritic, erythematous, serpiginous tracks on the dorsal aspect of his right foot after returning from a beach vacation in the Caribbean. What is the standard first-line treatment for this condition?

   1. A.Permethrin 5% cream
   2. B.Oral Ivermectin
   3. C.Oral Fluconazole
   4. D.Topical Ciprofloxacin
   See the answer and solution
3. Question 3Q-BF9757

   A 10-year-old child presents with honey-colored crusted lesions around the nose and mouth. Removal of the crusts reveals an erythematous, moist base. Which of the following toxins produced by the causative organism is primarily responsible for the development of bullous impetigo?

   1. A.Erythrogenic toxin
   2. B.Exfoliative toxin A and B
   3. C.Toxic shock syndrome toxin-1 (TSST-1)
   4. D.Panton-Valentine leukocidin
   See the answer and solution
4. Question 4Q-0E2D12

   A 30-year-old male presents with hypopigmented macules on his upper trunk and back that show a fine scale when scratched (Zileri's sign). Direct microscopic examination of skin scrapings treated with 10% KOH reveals short, stubby hyphae and clusters of spores, classically described as 'spaghetti and meatballs'. What is the diagnosis?

   1. A.Tinea versicolor
   2. B.Vitiligo
   3. C.Pityriasis alba
   4. D.Progressive macular hypomelanosis
   See the answer and solution
5. Question 5Q-74A594

   A 45-year-old farmer presents with a chronic, painless nodule on his right index finger that ulcerated, followed by the appearance of a chain of subcutaneous nodules tracking proximally up his arm along lymphatic channels. What is the most likely causative agent?

   1. A.Sporothrix schenckii
   2. B.Mycobacterium marinum
   3. C.Actinomyces israelii
   4. D.Blastomyces dermatitidis
   See the answer and solution