Laboratory Reference

Overview of Laboratory & Office Tests

Office Tests
These procedures can be performed in the office, with immediate results.

Gross Microscopy
Plain microscopy can be useful for analyzing species of mites and lice.

10% KOH prep
Adding 10% KOH solution during microscopic examination will allow confirmation of fungal infections.
Wood's Lamp Certain microorganisms will fluoresce when the specific wavelength of Wood's lamp illuminates a region of skin. Useful in diagnosing dermatophyte infections, especially tinea capitis, and is also useful for diagnosis of erythrasma.
Laboratory Tests
Lab procedures require that a specimen be transported off-site for examination. Results may take up to a week.
Biopsy A biopsy can be both diagnostic and therapeutic, therefore, it is included in both this reference and the treatment reference. The three types of biopsies are shave, punch, and elliptical.
Cultures Bacterial cultures are not routinely performed because the pattern of dermatologic lesion is often indicative of the offending bacteria. However, HSV and fungal cultures are often of use in confirming a diagnosis or verifying the species of fungus involved. (Note that HSV culture has been replaced in some centers by the direct fluorescent antibody test, with a 2-day turnaround time).
Serology Serology is used to evaluate for certain systemic conditions that can manifest with skin symptoms. Examples used in dermatologic diagnosis include ANA, VDRL, HIV, Lyme titer and Hepatitis B surface antigen.