Fig. 3. Radiofrequency (RF) promoted neocollagenesis and restored basement membrane. Increased number of cells expressing procollagen-1 was observed in the dermis after the RF treatment. Immunostaining for type IV collagen showed that disrupted basement membrane in melasma skin was restored after the RF treatment. However, significant changes in the vascularity and the number of mast cells were not observed in the dermis through the immunostaining for CD31 and mast cell tryptase. Original magnification ×200. ^*Statistically significance (p<0.05).