Characterization of Epidermal Function in Individuals with Primary Cutaneous Amyloidosis

Figures & data

Table 1 Demographic Characteristics of Participant

Parameter	LA (n=135)	MA (n=54)	Controls (n=166)	p value
Age (yr)	42.76±10.49	44.19±9.17	41.28±9.44	0.372^a
Age of onset	35.11±7.96	33.73±9.15		0.071
Males	85(63.0%)	6(11.1%)	79	p<0.0001^b
Females	50(37.0%)	48(88.9%)	87	p<0.0001^b
Severity of pruritus (VAS)
0	18(13.3%)	23(42.6%)		p<0.0001^b
I (>0 to <3)	51(37.8%)	22(40.7%)
II (≥3 to <7)	39(28.9%)	8(14.8%)		p=0.0614^b
III (≥7 to <9)	27(20.0%)	1(1.9%)		p=0.001^b
IV (≥9)	0	0

Notes: Data are expressed as mean ±SD. ^aMann–Whitney U-test was used to determine the significance among the three groups; ^bχ²-test was used to determine the significance between LA and MA.

Abbreviations: LA, lichenoid amyloidosis; MA, macular amyloidosis.

Figure 1 Clinical and pathological features of PCA patients. (A) Typical rippled hyperpigmented patches on the back and (B) papular lichenoid on the shin. (C) Congo red positive amyloid deposits in PCA patients (Congo Red stain, x200, arrow). (D) The amyloid deposits in the papillary dermis (H&E, x400, arrow).

Table 2 Comparison of Epidermal Biophysical Properties

Parameter	Nape	Back	Shin	Forearm^a
TEWL (g/hr/m^2)
Controls (n=166)	6.62 ± 3.03	6.86 ± 2.86	7.34 ± 2.94	7.36 ±3.54
LA (n=135)	9.74 ± 2.99	10.54 ± 2.38	10.15 ± 3.12	7.13 ±3.01
MA (n=54)	9.24 ± 3.61	8.27 ± 2.48	7.50 ± 2.65	7.67 ± 2.40
Stratum Corneum Hydration (au)
Controls (n=166)	27.52 ± 6.58	27.80 ±7.04	28.54 ± 6.62	28.39 ± 6.64
LA (n=135)	20.13±5.11	18.62±5.42	18.49±5.20	28.33±6.69
MA (n=54)	21.82±5.68	21.65±4.20	24.35±4.61	27.35±5.40
pH
Controls (n=166)	5.34 ± 0.50	5.28 ± 0.48	5.19 ± 0.42	5.15 ± 0.56
LA (n=135)	5.70 ± 0.38	5.81±0.47	5.68 ± 0.44	5.19 ± 0.49
MA (n=54)	5.53 ± 0.52	5.60±0.44	5.50±0.52	5.29 ± 0.47
Sebum content (ug/cm^2)
Controls (n=166)	76.36 ± 8.07	74.55±8.49	73.02±9.13	74.45±8.54
LA (n=135)	59.30 ± 7.22	56.65±6.77	57.93±7.31	74.17±5.66
MA (n=54)	61.79 ± 7.32	63.65±5.84	64.15 ±6.81	73.41±6.60

Notes: ^aThe measurement site was the flexor forearm, 10cm above the wrist. The forearm served as the uninvolved skin site in PCA patients. Data are expressed as mean ± sem. P values are indicated in Figure 2.

Abbreviations: TEWL, transepidermal water loss; LA, lichenoid amyloidosis; MA, macular amyloidosis.

Figure 2 Comparison of the Epidermal Biophysical Properties among LA, MA and normal controls.(A) TEWL; (B) stratum corneum levels; (C) skin surface pH, and (D) skin sebum content. *p<0.05; **p<0.01; ***p<0.001; ****p<0.0001.

Figure 3 Correlation of epidermal biophysical properties with the severity of pruritus. The level of TEWL (A), SCH (B), PH value (C), and Surface sebum content (D) were correlated with the severity of pruritus, and with the increase of pruritus severity, the value of epidermal biophysical properties increased or decreased accordingly.

Notes: Solid line represents the data analysis of the back; dotted line represents the data analysis of the shin.