The era of molecular diagnostics in dermatology and dermatopathology is upon us. Advances in genomics are continually redefining our understanding of the pathogenesis and classification of skin diseases. Molecular diagnostic strategies are now becoming an important adjunct to clinical and histopathological findings in the clinical management of individuals with these disorders. Molecular testing is transforming patient care, facilitating diagnosis of diverse cutaneous conditions, including the staging and prognostication of cutaneous malignancies, guiding the selection of appropriate therapy, monitoring of treatment efficacy, and identification of novel therapeutic targets. An understanding of the principles and potential applications of molecular technologies is now essential for any physician practicing in this field.  

Nucleic acid amplification methods [i.e., polymerase chain reaction (PCR)] have traditionally dominated this area of laboratory testing. Newer technologies are now being incorporated, facilitating parallel gene analyses  (i.e., cDNA/oligonucleotide microarrays) and correlation of genomic changes with morphological features of disease [i.e., fluorescence in situ hybridization (FISH)]. 

Laboratory testing accounts for only ~5% of hospital costs, but influences 60-70% of all treatment decisions. The molecular diagnostics market is forecasted to more than double over the next half decade, increasing by ~18% per annum. This is compared with only ~5% for other laboratory tests. The uptake of molecular testing has been slower in dermatology compared with other clinical specialties. A recent PUBMED search determined that only ~2% of molecular diagnostic articles in the scientific literature are dermatology-focused. The textbook “Molecular Diagnostics in Dermatology and Dermatopathology” describes potential ways to broaden the use of nucleic-based technologies in these fields.