A 24 year old man presented with multiple small hypopigmented macules around hair follicles on upper chest and back. Scratching of the lesion with a glass slide showed fine scaling. Which of the following is the investigation of choice in diagnosing this condition?
Patient is showing features of Pityriasis Versicolor caused by Malassezia furfur. Lesions appear as hypopigmented, scaly, perifollicular macules which coalesce together. It is diagnosed using KOH mount of the lesion which shows a mixture of sho branched hyphae and spores (spaghetti and meat ball appearance). Ref: Illustrated Synopsis of Dermatology and Sexually Transmitted Diseases By Neena Khanna 2ND edn page 245.
KOH preparation of scales
Tzank test
Slit Skin Smear Examination
Skin biopsy of lesion