<prompt> Erythematous lesions seen in axilla with coral red fluorescence in woods lamp is:TineaLichen planusErythrasmaVitiligo  <response>: Ans: c Erythrasma Ref: Pavithrans Textbook 56Erythrasma is a chronic infection of skin caused by Corynebacterium minutissimum and affects the intertrigenous areas like the axillae, toe, webs and groin.It is asymptomatic in nature and absence of central clearing helps to differentiate it from tinea.Extensive lesions may occur in patients with diabetes mellitus.Underwoods light the affected area shows a coral red fluorescence. This is due to the presence of porphyrins produced by the coryne bacterium minutissimum.Woods lamp lightMade up of nickel oxide and silica. It generates 360nm UV-A light. Corynebacterium minutissimum-coral red colour. Pseudomonas, psoriasis-pale blue. Tuberous sclerosis-ash leaf spotsblue white Vitiligo-chalky white. Porphyria cutanea tarda-pinkish red urine Tinea versicolor-golden fluorescence. Tinea capitis-yellow fluorescence Sq cell ca-red fluorescence. Albinismleprosy-blue white 