NIC Esthetician Written ExamSkin Analysis and ConsultationMedium
An esthetician is performing a skin analysis and notes that the client's skin has a yellowish-green fluorescence under a Wood's lamp. This observation is most indicative of which of the following conditions?
- APseudomonas infection
- BPropionibacterium acnes
- CPityrosporum folliculitis
- DTinea corporis
Show answer & explanationAnswer & explanation
Correct answer: C. Pityrosporum folliculitis
A yellowish-green fluorescence under a Wood's lamp is characteristic of Pityrosporum folliculitis (also known as Malassezia folliculitis), caused by an overgrowth of yeast. While some bacteria (like P. acnes) can fluoresce, and other fungi exist, the specific yellowish-green color is a key indicator for Pityrosporum.
Why the other options are wrong
- A. Pseudomonas infection can sometimes show a green fluorescence (pyoverdin), but it's less common on the skin surface and distinct from the yellowish-green of Pityrosporum.
- B. Propionibacterium acnes (now Cutibacterium acnes) typically produces an orange-red fluorescence under a Wood's lamp, not yellowish-green.
- D. Tinea corporis (ringworm) does not typically fluoresce under a Wood's lamp, or may show a dull green if caused by certain dermatophytes.
Wood's Lamp Fluorescence: Yellowish-Green
A yellowish-green fluorescence under a Wood's lamp indicates the presence of Pityrosporum (Malassezia) yeast, often associated with folliculitis.
- Caused by Malassezia furfur yeast.
- Often presents as small, itchy papules/pustules.
- Common in oily areas like chest, back, forehead.
- Distinct from orange-red (P. acnes) or coral pink (Erythrasma).
Memory trick: Wood's lamp lights up skin issues in distinct hues.