Gentian violet has been shown to have antibacterial, antifungal, antiviral, antihelminthic, and antitrypanosomal properties, but its efficacy has been mostly demonstrated against Streptococcus, methicillin-sensitive and methicillin-resistant Staphylococcus aureus, and Candida.3 Given the dermatologic relevance of these organisms, gentian violet is a favorite among attendings at my residency program; it is not uncommon to remove a patient’s dressing and uncover an iatrogenically purple wound. Best of all, pediatric patients are invariably amused when they see someone drawing on their skin with a purple marker.
When using a sterile surgical marker to apply gentian violet to the skin, we use either the marker tip or the ink core, which Dr. Siegel taught me can be easily accessed by snapping most plastic markers in half.
Item 3: Handheld Blacklight
The Wood lamp is a useful tool in the diagnosis of various infectious diseases and pigmentary disorders,4 but it is not always practical to use when on call, as standard ones are relatively large and corded, so they must be plugged into an electric outlet to work. You can therefore imagine the gratitude I have for my co-residents Miriam Lieberman, MD; Jaime Alexander, MD; Nicole Weiler, MD; and Alessandra Haskin, MD, for introducing me to the most convenient Wood lamp: the handheld blacklight. For less than $10, this gadget combines the diagnostic power of UV light with the portability of a pocket-sized, battery-powered flashlight. You will never want to use another Wood lamp again.
Item 4: Normal Saline Flush
Normal saline can be used for more than storing specimens for frozen section or tissue culture; it also can substitute for Michel solution when storing specimens for direct immunofluorescence (DIF) studies. I learned this tip from Edward Heilman, MD, a dermatopathologist at Downstate. For the last 20 years, Dr. Heilman has been successfully storing DIF specimens in refrigerated normal saline for up to 24 hours when Michel solution is unavailable, after which the specimen is processed or transferred to Michel solution for further storage while being transported to an immunofluorescence laboratory.
In 2004, Vodegel et al5 formally studied this technique in 25 patients with autoimmune skin diseases such as pemphigus and pemphigoid. (Thanks to Dr. Lieberman for telling me about this study.) The experiment involved taking 4 punch biopsies from each patient and placing them in either normal saline at −80°C for 24 or 48 hours, room temperature Michel solution for 48 hours, or liquid nitrogen for up to 2 weeks before being processed for DIF and analyzed by a blinded interpreter. Interestingly, specimens stored in normal saline for 24 hours were the most diagnostic, with a conclusive diagnosis reached in 21 of 25 specimens (84%). This result was attributed to the statistically significant reduction (P<.01) in background fluorescence with normal saline compared to Michel solution and liquid nitrogen, which in turn allowed for easier detection of diagnostic immunoreactants. Similar to Dr. Heilman, the authors cautioned against placing DIF specimens in normal saline for more than 24 hours; in their experience, the risk for an artefactual split developing at the dermoepidermal junction increases with this practice.5