Intermediate Hair Follicles: A New, More Clinically Relevant Model for Hair Growth Investigations

In the study by Miranda et al., researchers analyzed 250 hair follicles morphometrically from five individuals and observed 210 follicles in organ culture from six individuals to compare intermediate and terminal hair follicles. They found that intermediate follicles were smaller, less pigmented, and penetrated less below the skin surface with smaller fiber, connective tissue sheath, bulb, and dermal papilla diameters than terminal follicles. In organ culture, intermediate follicles grew more slowly, stayed in the anagen phase longer, and produced less hair fiber. Despite the technical challenges, the study concluded that intermediate follicles are a more clinically relevant model for hair growth investigations, particularly for conditions like alopecia, and could be important for testing new treatments for hair loss disorders. The study involved microdissecting 25 terminal and 25 intermediate hair follicles from each of six white women, highlighting the potential of intermediate follicles as a new model system for hair regrowth studies.