Wood’s light does the trick
On asking a pharmacist to recommend a dermatologist, the young man came to see me. He has seen five professors in vain, one of whom biopsied his skin disease with non-specific histopathological findings. While listening to the history, I immediately saw the difficulty in reaching the correct diagnosis. Various diagnoses have been made by the colleagues, e.g. insect bites and scabies. One of the professors has prescribed systemic steroid for the “unknown skin disease”. Four of the professors had gathered to discuss his case at university in vain before the fifth professor biopsied his skin disease. From time to time, Wood’s light does the trick. There were scratch marks and conspicuous lichenification involving many areas including the groins and the perianal skin. Presence of extensive coral-red fluorescence under Wood’s light clinched the diagnosis. Erythrasma can certainly be symptomless but scratching leading to lichenification might occur. This was the first time for him to be examined under Wood’s light and the erythrasma patches were apparently difficult to see by the colleagues because of his hairy skin. Coral-red fluorescence with Wood’s light is attributable to coproporphyrin III and strongly suggests erythrasma.
This page was last updated in March 2012.