Are quantitative histopathologic criteria capable of differentiating psoriasis from chronic dermatitis?

Figures & data

Figure 1 (A) Histopathology of psoriasis (H&E ×100). (B) Histopathology of chronic dermatitis (H&E ×100).

Notes: [img] Width of the longest rete ridge; [img] minimal thickness of granular layer; [img] thickest part of parakeratosis; [img] length of the longest rete ridge; [img] minimal thickness of suprapapillary plate.

Table 1 Comparison of quantitative histopathologic parameters between chronic dermatitis and psoriasis

Variables	Psoriasis				Dermatitis				p-value (Mann–Whitney)
	Mean	SD	Min	Max	Mean	SD	Min	Max
Rete ridge length (μm)	4479.6	1438.3	2388.9	8177.5	2369.4	849.8	1318.4	4810.5	0.001
Rete ridge width (μm)	1053.9	369.3	355.9	1800.6	580.4	279.1	264.1	1160.7	0.001
Thickness of suprapapillary plate (μm)	498.2	218.5	67.5	4371.6	621.6	739.1	248.7	4431.8	0.022
Thickness of epidermis (μm)	5047.2	1478.6	2763.2	8625.3	2487.6	883.1	1318.4	4810.5	0.001
Thickness of granular layer (μm)	41.7	31.9	0	107.9	133.9	55.2	48.4	294.4	0.001
Thickness of parakeratotic layer (μm)	1228.6	1014.5	400.5	5764.3	1130.8	1181.1	228.4	5377.8	0.094

Table 2 Comparison of quantitative histopathologic parameter ratios between chronic dermatitis and psoriasis

Ratios	Psoriasis				Dermatitis				p-value (Mann–Whitney)
	Mean	SD	Min	Max	Mean	SD	Min	Max
Width to length of rete ridge	0.256	0.116	0.063	0.533	0.251	0.109	0.109	0.564	0.964
Suprapapillary plate’s thickness to epidermal thickness	0.120	0.226	0.010	1.29	0.278	0.377	0.082	2.23	0.001
Granular layer’s thickness to parakeratotic layer’s thickness	0.045	0.042	0	0.133	0.182	0.113	0.050	0.500	0.001

Figure 2 ROC curve for granular layer’s thickness to parakeratotic layer’s thickness ratio.

Abbreviation: ROC, receiver operating characteristic.

Figure 3 ROC curve for suprapapillary plate’s thickness to epidermal thickness ratio.

Abbreviation: ROC, receiver operating characteristic.