A method and system for rapidly detecting Candida on the skin of a host, such as an infant with diaper rash, is provided. The method includes contacting a dermal sample with a colorant that exhibits a certain spectral response (e.g., color change) in the presence of Candida. For example, the colorant may change from a first color to a second color, from colorless to a color, or from a color to colorless. The colorant is typically capable of differentiating between Candida (e.g., Candida albicans) and other microorganisms commonly associated with diaper rash, such as S. aureus and E. coli. Thus, when a dermal sample is placed into contact with the colorant, the color change may simply be observed to determine whether the infection is caused by Candida. If the color change occurs to a certain extent (e.g., from yellow to bright red), it may be determined that the test sample contains Candida. Likewise, if a color change occurs to a lesser extent (e.g., from yellow to faint orange) or not at all, it may be determined that the dermal sample contains other microorganisms (e.g., S. aureus or E. coli), no infection is present, or that the infection is simply due to other causes. Regardless, it will become readily apparent whether or not treatment for Candida is needed.