AAFM Boards Dermatology Practice Test

Erythrasma is a skin condition caused by the bacterium Corynebacterium minutissimum. When examined under a Wood's lamp, it typically demonstrates a distinctive fluorescence that is coral pink or orange in color. This characteristic fluorescence results from the porphyrins produced by the bacteria. The identification of erythrasma through this method is particularly important in differential diagnosis since other skin conditions may have different appearances under the Wood's lamp. For example, some fungal infections might show green fluorescence, while others, like certain types of bacterial infections, can appear with different hues. The unique coral pink or orange fluorescence of erythrasma helps healthcare professionals distinguish it from these other conditions, making Wood's lamp examination a useful tool in dermatological practice.