fig1

Figure 1. Evaluation of hair loss by patients and clinician with our phototrichogram method and scalp coverage scoring. Figure 1 illustrates all the techniques used throughout this study. Figure 1A and B displays cartoons employed by investigator and patients. From normal coverage or no visible hair loss [Figure 1A; top left], the patients independently choose either no visible loss or FPHL split-up according to Ludwig stages [LI-LIII; bottom of Figure 1A] or MPHL [Hamilton stages HI-HV in Figure 1B]. Similarly, and without direct interaction with the patient’s record, the clinician classified subjects as having diffuse or patterned hair loss (PHL). The SCS [Figure 1C] was usually performed on the computer screen. This implies the subdivision of the image of the top of the head into 18 square fields surrounded by a circle, a symbolic outline of the head. With the hair combed as spokes of a wheel, SCS was evaluated in 2 different ways: first scoring the nine numbered fields that include top and vertex [Figure 1C, top; 1-9 bold] followed by the nine other fields with more lateral and anterior locations [Figure 1C, top; italic light]. Finally, on the image taken after parting hair along the midline, coverage was estimated in each of the four squares labelled p1-p4 [Figure 1C, bottom]. At the end of the clinical visit, the investigator selected a region of interest (ROI). This site served for detailed hair growth measurements employing the CE-PTG-EC [Figure 1D]. Our phototrichogram method is illustrated (modification of the original Figure 1 in the author’s publication to which we refer the interested reader^[15,16]). Classical and novel processing methods are illustrated in greater detail in Figures 11 and 12. Exogen collection is part of our phototrichogram method, as shown in the lower half of Figure 1D where three loosely attached telogen bulbs were entrapped in the blue matrix examined under a stereomicroscope. The schematic view [bottom of Figure 1D; arrowheads] illustrates the same 3 exogen hairs: Exogen 1 was deeply set in the follicle at completion of telogen; Exogen 2 was moving upwards in the hair follicle; and Exogen 3 almost reached the scalp surface for release in the nearby future. Figure 1E shows clinical examples of male subjects with MPHL according to Hamilton’s scale with hair combed as spokes of a wheel (left to right; severity Grades I-V). For the correct interpretation of data from the clinical perspective, readers are invited to keep three things in mind: (1) The frontal hairline does not appear in the global view and, as a consequence, should not interfere with SCS; (2) The variable shape/size of the head does not interfere with SCS as the scalp areas explored in a given subject are stable over time; and (3) ROI is remote from the epicentre of the balding process (white dot usually on the right side of patient’s top of the head). FPHL: Female pattern hair loss; MPHL: male pattern hair loss; SCS: scalp coverage scoring, CE-PTG-EC: contrast-enhanced phototrichogram with exogen collection.