14 clinical MCQs in Medical Mycology. Amphotericin B would be used to treat all of the following EXCEPT. Kenya, Africa and global revision.
Q1. Amphotericin B would be used to treat all of the following EXCEPT
Answer: Ergotism
Explanation: Ergotism is caused by ingesting ergot alkaloids from Claviceps purpurea — it is a toxin poisoning, NOT a fungal infection. Amphotericin B treats fungal infections only. ---
Q2. All of the following are superficial mycoses EXCEPT
Answer: Tinea pedis
Explanation: Tinea pedis (athlete's foot) is a cutaneous mycosis, not superficial. Superficial mycoses affect only the outermost skin layer with no tissue invasion. ---
Q3. Which of the following statements regarding Tinea nigra is NOT correct?
Answer: It is difficult to isolate by microscopic examination from skin scrapings
Explanation: Tinea nigra is actually EASILY identified microscopically — skin scrapings show septate hyphae and budding yeast cells. It is caused by Hortaea werneckii. ---
Q4. Which of the following is the common cause of Athlete's foot?
Answer: All of the above
Explanation: All three create the warm, moist environment that Trichophyton rubrum and T. mentagrophytes thrive in — the main causes of tinea pedis. ---
Q5. All of the following are characteristics of cutaneous mycoses EXCEPT
Answer: The common cause of ringworm in humans only
Explanation: Dermatophytes cause ringworm in both humans AND animals (zoophilic species like M. canis from cats/dogs). Not limited to humans only. ---
Q6. All of the following dermatophytes are responsible for nail infections EXCEPT
Answer: Microsporum canis
Explanation: Microsporum canis primarily infects hair and skin but does NOT typically cause nail infections (onychomycosis). The other three commonly cause nail infections. ---
Q7. Which of the following is an opportunistic pathogenic fungus in humans?
Answer: Candida albicans
Explanation: Candida albicans is normal flora that becomes pathogenic when immunity is compromised. The others are TRUE pathogens that can infect immunocompetent hosts. ---
Q8. Aspergillosis is recognized in tissue by the presence of
Answer: Septate hyphae
Explanation: Aspergillus shows characteristic septate hyphae with parallel walls and acute angle (45°) branching in tissue. NOT pseudohyphae (that's Candida). ---
Q9. Fungi often colonize lesions caused by other agents. Which is LEAST likely to be present as a colonizer?
Answer: Sporothrix
Explanation: Sporothrix schenckii is a primary pathogen causing sporotrichosis through traumatic implantation — it does NOT typically colonize pre-existing lesions. Candida, Mucor and Aspergillus are known colonizers. ---
Q10. Which statement regarding dermatophytosis is correct?
Answer: Acute infections are associated with zoophilic dermatophytes such as M. canis
Explanation: Zoophilic dermatophytes (from animals) cause ACUTE, highly inflammatory infections in humans because humans are not their natural host. Anthropophilic ones cause chronic, mild infections. ---
Q11. All of the following are examples of superficial mycoses EXCEPT
Answer: Tinea imbricate
Explanation: Tinea imbricate (caused by T. concentricum) is a CUTANEOUS mycosis involving deeper skin layers — not superficial. The others affect only the outermost skin surface. ---
Q12. Which of the following is NOT a characteristic of histoplasmosis?
Answer: Person to person transmission
Explanation: Histoplasmosis is NOT transmitted person to person. Infection occurs by inhaling spores from soil contaminated with bird/bat droppings. Endemic to Mississippi/Ohio River valleys. ---
Q13. You have made a clinical diagnosis of meningitis in a 50-year-old immunocompromised woman. A latex agglutination test on spinal fluid for capsular polysaccharide antigen is positive. Which is the most likely cause?
Answer: Cryptococcus neoformans
Explanation: The latex agglutination test for CAPSULAR POLYSACCHARIDE antigen is the classic confirmatory test for Cryptococcus neoformans meningitis. ---
Q14. Compare Eumycetoma and Actinomycetoma — which is correct?
Answer: Eumycetoma is caused by true fungi; Actinomycetoma by bacteria like Nocardia
Explanation: Eumycetoma = true fungal cause (e.g. Madurella). Actinomycetoma = caused by filamentous bacteria (Nocardia, Actinomyces). Important distinction — Actinomycetoma responds to antibiotics NOT antifungals.