What is the characteristic finding on KOH prep for tinea versicolor?

What is the characteristic finding on KOH prep for tinea versicolor?

• A. Hyphae and spores arranged as spaghetti and meatballs
• B. Septate hyphae only
• C. Bacteria seen within scaliness
• D. No organisms visible

Answer: (A)

On KOH prep for tinea versicolor, you look for a mix of yeast forms and short hyphal elements. Malassezia furfur, the organism behind tinea versicolor, appears as rounded yeast cells together with slender, spaghetti-like hyphae, giving a distinctive "spaghetti and meatballs" pattern. This combination distinguishes it from infections caused by true dermatophytes, which tend to show hyphae that are septate but lack the yeast-arthroconidia mix. The presence of bacteria or a lack of visible organisms wouldn’t explain the familiar fungal elements seen with tinea versicolor, and the KOH prep is what makes these elements visible by dissolving keratin.

On KOH prep for tinea versicolor, you look for a mix of yeast forms and short hyphal elements. Malassezia furfur, the organism behind tinea versicolor, appears as rounded yeast cells together with slender, spaghetti-like hyphae, giving a distinctive "spaghetti and meatballs" pattern. This combination distinguishes it from infections caused by true dermatophytes, which tend to show hyphae that are septate but lack the yeast-arthroconidia mix. The presence of bacteria or a lack of visible organisms wouldn’t explain the familiar fungal elements seen with tinea versicolor, and the KOH prep is what makes these elements visible by dissolving keratin.