Response to Letter to the Editor on Inflammation in Androgenetic Alopecia

In response to a letter by Dr. Valdebran regarding the role of inflammation in androgenetic alopecia (AGA), Dr. Neil Sadick and Dr. Cynthia Magro discussed their own 2011 histopathological study and compared it with Dr. Valdebran's findings and the seminal study by Dr. David Whiting. Sadick and Magro's study found that most cases of AGA were associated with lymphocytic folliculitis and significant deposits of IgM immunoglobulin, suggesting that a targeted lymphocytic reaction within the follicle bulge could be implicated in hair miniaturization. They noted that their study lacked healthy control biopsies, which was a significant drawback. Whiting's study found inflammation or fibrosis in 70% of AGA cases compared to 40% of controls, with those showing significant inflammation or fibrosis less likely to respond to minoxidil. Sadick and Magro criticized Dr. Valdebran's study for using one vertical section, which limited the number of hairs available for inspection, and for using excision specimens as controls instead of matched punch biopsies. They concluded that it is difficult to dismiss inflammation and fibrosis as important factors in AGA without considering other studies and suggested a corroborative study with more stringent control samples to resolve questions surrounding inflammation and fibrosis in AGA.