Dermatophyte infections are caused by which type of organism?

• A. Bacteria
• B. Fungi
• C. Viruses
• D. Protozoa

Answer: (B)

Dermatophyte infections are caused by fungi. Dermatophytes are fungi that specialize in feeding on keratin found in skin, hair, and nails, which is why they produce ringworm–type infections. They grow as hyphae and reproduce by spores, and their common culprits include the genera Trichophyton, Microsporum, and Epidermophyton. This fungal nature distinguishes them from bacteria (prokaryotes), viruses (noncellular pathogens), and protozoa (single-celled organisms that are not fungi). Because they are fungi, treatment involves antifungal medications rather than antibiotics, a distinction you’ll encounter in clinical practice and when advising clients. In esthetics, it’s important to recognize signs of these infections and avoid procedures on affected areas to prevent spread.