The current standard biopsy technique for the investigation of skin disease is a series of 3-5 mm skin punch biopsies. Experts can take one or two samples from the perfect primary lesion; most of us would be better advised to take at least a single sample from every macroscopic variant we can identify! There is no golden rule about whether you are better to take the center of the lesion, the periphery, or adjacent normal skin since it varies from disease to disease. Taking at least one biopsy from normal skin is an excellent idea. And, by the way: if you are going to carefully describe each lesion in terms of character and location, then do not waste that effort by throwing all of the samples into the same bottle! If you think it is important that the pathologist know which biopsy comes from which exact location, then they must be placed in separate bottles or identified by colored suture or some other foolproof method. Samples never, ever stay adherent to tongue depressors!

. . . and remember: skin biopsy should not be the diagnostic message of last resort after you have exhausted every drug in the pharmacy! As in all other pathology, the diagnostic specificity of skin lesions is greatest early in the disease, and falls progressively over time. If your first course of therapy based on clinical criteria has had no effect, then THAT is the time for biopsy!